quote:

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Cause of Death Probability
Motor Vehicle Accident 1 in 100
Homicide 1 in 300
Fire 1 in 800
Firearms Accident 1 in 2,500
Electrocution 1 in 5,000
Aircraft Accident 1 in 20,000
Asteroid Impact
1 in 25,000
Flood 1 in 30,000
Tornado 1 in 60,000
Venomous bite or sting
1 in 100,000
Fireworks accident 1 in 1 million
Food Poisoning 1 in 3 million

Table 1: Causes of Unnatural Death in the USA

These figures (after Chapman and Morrison) were accepted at the time, but a growing number of scientists feel that the figure for Asteroid Impact is too low by a likely factor of two, and should be closer to one in 10,000. The figures also fail to demonstrate the qualitative difference between individual events, such as the majority of cases in the table above, and the sudden, but massive loss of life caused by a major impact event.

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quote:

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Using radar and optical measurements made over the past 51 years, researchers have calculated that there is up to a one-in-300 possibility that Asteroid 1950 DA will slam into Earth on March 16, 2880. Their work is published in the April 5 issue of Science.

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quote:

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Diameter d Frequency of the impact
d>10 Km every 50 millions years
1Km<d<10Km every 500.000 years
100m<d>1Km every 5.000 years
30m<d<100m every 500 years

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quote:

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Chapman said the most likely international disaster that would result from an impact is a gigantic tsunami. A wall of water swamping islands and coastal communities would result from an ocean impact by an object a few hundred meters (yards) in size, he said.

"There is a 1-percent chance of something like that happening in the next century," Chapman said. But those organizations and individuals responsible for warning, or heeding warnings, about earthquake-generated tsunamis are generally unaware of impact-induced tsunamis, he said.

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quote:

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The probability of being killed by an asteroid is very low, but it is
larger than the chances of being killed by many other things (e.g.,
defective food or drugs, or leakage from nuclear power plants) that
governments take very seriously.

Impacts are the extreme example of a hazard of very low probability
but very great consequences.

Impacts are the only known natural hazard that could destroy civilization.

Asteroid impacts are the only known natural hazard that can be
eliminated entirely by appropriate application of technology.

---

quoted from David Morrison of NASA's Ames Research center.
 

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Posted by Morbo (Member # 5309) on :
 
ak, shouldn't you be saving Iraq about now? The Earth can wait.

I agree that NEO (Near Earth Objects) should be catalogued and studied more. Also, any improvement in extra-Lunar orbit spaceflight (especially manned) would be the first step to stopping an impact-threatening asteroid from impacting. Research about methods of asteroid orbit deflection and other tactics is important too- currently, that is only at the thought-experiment stage, for the most part. There needs to be real-world experimentation in that.

But it's human nature for people to worry and fret about terrorists and SARS and other low- probability threats instead of what's really liable to kill them, i.e. obesity, cancer, car crashes and other high-probablity but mundane threats. And politicians won't fund what they aren't bugged about. Most NEO cataloguing is low-priority work, often done by volunteers, IIRC.
 

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Posted by Morbo (Member # 5309) on :
 

quote:

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Impacts are the only known natural hazard that could destroy civilization

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quote:

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From Donald K. Yeomans and Robert McMillan:

The scientific community has come to realize that the hazard to Earth from asteroid and comet collisions is comparable to other natural disasters such as earthquakes, volcanoes and floods, differing not in terms of "average fatalities per year" but mainly in terms of frequency of occurrence. Although no significant number of deaths by asteroid or comet collisions have occurred in all of recorded history, major impact events are expected on time scales of about 500,000 years. Impacts of these so-called Near-Earth Objects (NEOs) have catastrophically disrupted the Earth's ecosystem in the past. Unless checked, these disasters will occur again; the question is when - not if. While events of this type could cause billions of fatalities from a single strike, impacts of these so-called Near-Earth Objects (NEOs) are avoidable. NEO impacts are the only type of serious natural disaster for which accurate predictions can be made and for which the technology exists for successful mitigation efforts.

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quote:

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Statistically, the chances of being killed by an asteroid are about 1in 5,000, which is greater than the chance of being killed in a plane crash. It's just that the incidences of asteroid impact are fewer and further between. Based on these probabilities, we are seriously underfunding this effort compared to the dollars we are spending on air safety.

---

[ November 15, 2003, 02:37 AM: Message edited by: ana kata ]
 

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Posted by Morbo (Member # 5309) on :
 
ak, no more lattes for you!

It's late, I'm crashing. Wake me if we're all doomed.
 

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Posted by ana kata (Member # 5666) on :
 

quote:

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"The Aztecs had believed the world would end in one of four ways: earthquake, fire, flood, or jaguars falling from the sky. Here there would be no fire. Nor earthquake nor flood, now that he thought of it. Leaving only the jaguars ... " - Kim Stanley Robinson, Red Mars, p. 14

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quote:

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5 And it came to pass in the thirty and fourth year, in the first month, on the fourth day of the month, there arose a great storm, such an one as never had been known in all the land.

6 And there was also a great and terrible tempest; and there was terrible thunder, insomuch that it did shake the whole earth as if it was about to divide asunder.

7 And there were exceedingly sharp lightnings, such as never had been known in all the land.

8 And the city of Zarahemla did take fire.

9 And the city of Moroni did sink into the depths of the sea, and the inhabitants thereof were drowned.

10 And the earth was carried up upon the city of Moronihah, that in the place of the city there became a great mountain.

11 And there was a great and terrible destruction in the land southward.

12 But behold, there was a more great and terrible destruction in the land northward; for behold, the whole face of the land was changed, because of the tempest and the whirlwinds, and the thunderings and the lightnings, and the exceedingly great quaking of the whole earth;

13 And the highways were broken up, and the level roads were spoiled, and many smooth places became rough.

14 And many great and notable cities were sunk, and many were burned, and many were shaken till the buildings thereof had fallen to the earth, and the inhabitants thereof were slain, and the places were left desolate.

15 And there were some cities which remained; but the damage thereof was exceedingly great, and there were many in them who were slain.

16 And there were some who were carried away in the whirlwind; and whither they went no man knoweth, save they know that they were carried away.

17 And thus the face of the whole earth became deformed, because of the tempests, and the thunderings, and the lightnings, and the quaking of the earth.

18 And behold, the rocks were rent in twain; they were broken up upon the face of the whole earth, insomuch that they were found in broken fragments, and in seams and in cracks, upon all the face of the land.

19 And it came to pass that when the thunderings, and the lightnings, and the storm, and the tempest, and the quakings of the earth did cease—for behold, they did last for about the space of three hours; and it was said by some that the time was greater; nevertheless, all these great and terrible things were done in about the space of three hours—and then behold, there was darkness upon the face of the land.

20 And it came to pass that there was thick darkness upon all the face of the land, insomuch that the inhabitants thereof who had not fallen could feel the vapor of darkness;

21 And there could be no light, because of the darkness, neither candles, neither torches; neither could there be fire kindled with their fine and exceedingly dry wood, so that there could not be any light at all;

22 And there was not any light seen, neither fire, nor glimmer, neither the sun, nor the moon, nor the stars, for so great were the mists of darkness which were upon the face of the land.

23 And it came to pass that it did last for the space of three days that there was no light seen; and there was great mourning and howling and weeping among all the people continually; yea, great were the groanings of the people, because of the darkness and the great destruction which had come upon them.

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quote:

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The task force, which comprised Sir Crispin Tickell, Professor David Williams and myself (as chairman), reported in September that the risk was indeed real and comparable with other low probability but very high consequence risks taken seriously by governments. The threat from NEOs raises major issues, among them the inadequacy of current knowledge, confirmation of a hazard after initial observation, disaster management, methods of mitigation and deflection, and reliable communication with the public.

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quote:

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Indeed the risk of death from an asteroid impact is estimated at 1 in 25,000, about the same as dying from a plane crash (1 in 20,000), and 100 times more likely than being killed by BSE or any form of food poisoning.

---

Another.
 

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Posted by aspectre (Member # 2222) on :
 
Phaethon's Ride
 

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Posted by ana kata (Member # 5666) on :
 
And take a look at Shoemaker Levy 9 hitting Jupiter. I saw this one in the telescope. Very exciting. Wouldn't have wanted to be closer.

Here is a time lapse sequence of the first impact. Remember that Jupiter is many times the size of earth. Some of the smaller features visible here are the size of our whole planet.
 

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Posted by prolixshore (Member # 4496) on :
 
Ummmm....I had you figured as relatively sane up til now. Theres a fine line between caution and paranoia.



Wishful thinking or not, I'm pretty sure we will all be fine. Of course the probability seems high when there are an infinite number of unknown objects in the sky. Let's relax and come back to reality where asteroid impacts don't happen as often as they do in imagination land.



--ApostleRadio
 

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Posted by Tresopax (Member # 1063) on :
 

quote:

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Tres, your rejection of the liklihood of this possibility seems to be based on wishful thinking and not much else. Trustworthy predictions I've seen range from 1 in 12,000 to 1 in 5,000 in a century.

---

quote:

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It's your chance of death, Tres. These guys are not stupid, sheesh! You think something so obvious has escaped them? <laughs> (You are not arrogant, are you?)

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That's a bit. . . uncalled for, isn't it?

quote:

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It astonishes me that people would rather not be told this. <laughs>

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What gives you the idea that people would rather not be told this?
 

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Posted by Occasional (Member # 5860) on :
 
I can't tell if you are seriously worried, or just having some fun on account of a possible destruction of the world.

As for me, I'm moving to Mars to watch the fireworks.
 

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Posted by ana kata (Member # 5666) on :
 
It's certainly a real threat, so yes, I am worried that we will do nothing until it's too late. We've been incredibly lucky thus far, as judged by the near misses we've seen.

Morbo, I'm still going to Iraq to do what I can there, but once we see one headed straight down our throats, Iraq and all the other problems we focus on worldwide day to day and year to year will seem pretty insignificant by comparison.

(P.S. Morbo, Novas, Supernovas, Gamma Ray Burstars, and also galaxies in collision (which Slashy was worried about the other day) are other things that could destroy our whole civilization, but there truly isn't anything we can do about them in the near future. Asteroid impacts we can actually prevent.)

And I'm willing to take it all lightly, provided we seriously get to work on it. Soon.

[ November 15, 2003, 03:44 PM: Message edited by: ana kata ]
 

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Posted by Ron Lambert (Member # 2872) on :
 
In the past hundred years, there have been a few meteorite impacts that while not extinction level events for the whole globe, did hit with a force equivalent to several nuclear bombs. Fortunately these hit in sparsely populated wilderness areas. If the one that hit in Siberia in 1908 (the Tunguska Event) had hit London, it would have destroyed that city and most of the surrounding countryside. Millions would have died.

Here is a link to a list that includes meteorite impacts in modern times that have been witnessed. Many more undoubtably have fallen without any human observers around:
http://www2.state.id.us/bdsmitigation/asteroids.html

We are not "dodging the bullet." We are being hit. We've just been lucky so far that we haven't been hit in a vital spot.

That list I gave the link to above also includes two potential "earthbusters" that did in fact come close to the earth. One, a large asteroid named Toutatis, was four kilometers in diameter (big enough to have destroyed all life on earth) and it passed within two lunar distances of earth, in 1992. Another passed close by the earth in 1989, but was not discovered until after it had passed close by the earth, and its trajectory was projected backward.

The inner solar system is a shooting range, and we're being hit by cosmic shotgun blasts all the time. Some people are suggesting that there may be several events in modern human history that were affected directly or indirectly by large meteorite strikes, such as the "little ice age" that drastically cooled temperatures in Europe for over a century, and perhaps even the mysterious collapse of the Mayan Empire. Some people believe the Chicago fire of 1871 may have been caused by a meteorite (it is one of many theories anyway).

[ November 15, 2003, 03:57 PM: Message edited by: Ron Lambert ]
 

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Posted by Shepard (Member # 5613) on :
 
I'm not sure why you are telling Hatrack this. What is it going to do, fund its own Asteroid Defense Program? Sign a pettition to the government, begging them to spend billions of dollars on the small chance we all die anyway? If the asteroid was big enough, we'd all be dead, even if we knew months in advance that it was coming. The world doesnt even have a missle powerful enough to fly to the moon or wherever and blow up a massive asteroid. This paranoia isnt productive, it just scares people. There really is nothing that can be done, and if the matter is as pressing as you make it sound, nothing can be done fast enough anyway.
 

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Posted by ae (Member # 3291) on :
 
Shepard:

quote:

---

I'm not sure why you are telling Hatrack this.

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quote:

---

If the asteroid was big enough, we'd all be dead, even if we knew months in advance that it was coming.

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quote:

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There really is nothing that can be done. . .
The world doesnt even have a missle powerful enough to fly to the moon or wherever and blow up a massive asteroid.

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quote:

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P.S. Morbo, Novas, Supernovas, Gamma Ray Burstars, and also galaxies in collision (which Slashy was worried about the other day) are other things that could destroy our whole civilization, but there truly isn't anything we can do about them in the near future.

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quote:

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Why aren't we getting serious about this?

---

Cause, the last time a president wanted to put money into the space program to shoot things out of the sky, (From what was at the time, and come to think of it, still is a very real threat,) everyone laughed at him and called him a "chicken little looney."

I think it will be a while before another American president actively backs "Star Wars" type projectile defense technology. At least we have Patriot missiles.

Although, with all these daiperhead countries buying Russian nukes or developing their own, maybe "Star Wars" isn't such a bad idea.
 

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Posted by Morbo (Member # 5309) on :
 
Maccabeus, there is a statistical argument that answers your objection, but I cannot rememember the details of it. I'll try to look it up later.

However, just because we have not had a global catastrophe in the last few thousand years doesn't mean one will never happen again, or won't happen in this century.
 

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Posted by Morbo (Member # 5309) on :
 
Mazer, there were several reasons Star Wars missle defense was infeasible. Physicists not connected with the project doubted effective energy densities could be reached that would knock down missles thousands of miles away. Computer and systems analysts doubted that any system could manage information quickly enough to knock down thousands of Russian or Chinese ICBMs and decoys in any first strike scenario. Right and left wing political analysts thought it was inherently destabilizing to NATO/Russia/China relations. Not to mention the crippling costs of research and eventual deployment. It didn't stop Reagan from pouring billions of dollars into the program.

The current president has started a less ambitous strategic missle defense reseach project, with the goal of stopping a small number of ICBMs instead of a massive wave of them. This is why the US backed out of the ABM treaty a while ago, I think in 2001.
 

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Posted by Morbo (Member # 5309) on :
 

quote:

---

With all these daiperhead countries buying Russian nukes or developing their own, maybe "Star Wars" isn't such a bad idea

---

quote:

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I'm not sure why you are telling Hatrack this.

---

There are a lot of good reasons!

1. Because this is a discussion forum, and it's an interesting thing to discuss.

2. Because ana kata is concerned about it, and as her friends, we like to know what's going on in her life (such as what she is concerned about).

3. Because Hatrack is full of brainiacs, and maybe someone will have a good idea.

4. And so on.

It's all good.
 

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Posted by Alucard... (Member # 4924) on :
 
OK,

All I need is a monitor, some tracking software, a track ball, and access to some ICBMs. I mean, I played missle command a thousand times in the arcade.

Plan B would involve creating an orbiting series of "defense rings" in our outer orbit comprised of crappy automobiles like the Yugo. Think about it? Where did they all go? I NEVER see a Yugo anymore...

Coincidence?
 

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Posted by Occasional (Member # 5860) on :
 
One of the major problems with an asteriod defense system (that both movies overlooked) is you can't really neutralize the effects of the asteroid with current available technology. Hitting the asteriod with a nuclear bomb or its equivalant will only create large fragments. Instead of one large hit destroying life on earth, you will have multiple hits that end up doing the same damage.

They have thought of simply changing the trajecotry of the asteriod. However, that still has its complications in regard to the power needed for such a feat. Too far away or not strong enough and the tragectory change will be trivial. Too close, or too strong, and you end up with the fragmentary problem.

[ November 16, 2003, 04:15 PM: Message edited by: Occasional ]
 

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Posted by ssywak (Member # 807) on :
 
I need everyone, Alucard in particular, to look at this special pen I have.

Yes, look at the top end very carefully. Wait, let me get my glasses on...

>>>schvoomp<<

Yugoslavia has never made any automobiles. The Soviets have been re-labeling Fiats since the early 1970's. You are completely safe. Please return to your reglular lives.
 

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Posted by ana kata (Member # 5666) on :
 
Yes, it does no good simply to break it into fragments which all still hit the earth. The energy released would be the same in that case. It's necessary to either shove it off course completely so that it misses, or to blast it to smithereens so that the majority of the debris ends up on trajectories which do not intersect earth.

My thought for the next few years or decades until we have a moon base is to deflect them into the moon. There are a number of advantages to this plan.

1) We need to plan for all times. If we merely bump an asteroid with an earth crossing orbit a little bit, it remains a threat into the distant future. In 100 or 1000 years, will people on earth still maintain the capability to detect and counter the threat of an impact? Why not eliminate it entirely as a threat.

2) There's nothing on the moon to be damaged. No atmosphere. No life.

3) When we DO get around to building moon bases and structures, it would be super cool if there were a big chunk of nickle iron up there to be mined. As it is, on the moon, we have to either bring our materials from earth at prohibitive expense, or else make things out of glass. There's lots of silicone and other rocky stuff, but no iron for steel. Iron would come in real handy.

4) I have to admit the fireworks display would be really great. Close enough for thrills but not so close that we all die. <laughs> That's my idea of good fireworks.
 

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Posted by ana kata (Member # 5666) on :
 
CT, yes! For all those reasons and one more.

If the intelligent, literate, people of hatrack who have been exposed to real science fiction, are not citizens of the galaxy, and able to see the sense of this, then who on earth is? Hatrack's reaction must be assumed to be far more enlightened and favorable to the logic of this step than the public's at large.

Also I do see hatrack as the movers and shakers. If not now, then in a decade or so when those who are now in college end up running everything. If the world is to be saved, it will be by us. We are the ones with the knowledge and the understanding, and we are the ones who care.

That's rather a frightening thought, isn't it? <laughs>

[ November 16, 2003, 04:58 PM: Message edited by: ana kata ]
 

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Posted by Occasional (Member # 5860) on :
 
The problem with the Moon deflection plan is that a large enough hit could damage the Moon and cause a whole host of new deadly problems. It would depend on the size of the asteroid we are talking about. My thoughts are if we had the ability to deflect the asteriod we wouldn't need to send it toward the Moon anyway.
 

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Posted by ana kata (Member # 5666) on :
 
Occasional, what damage could it do to the moon? Cause a new crater? There's no atmosphere and nothing there to damage, so I can't see it causing any problems.
 

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Posted by Shepard (Member # 5613) on :
 
And to think, some people actually want to get rid of nuclear weapons. How can they say so, when they are our only salvation from asteroid impacts?
 

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Posted by Morbo (Member # 5309) on :
 
Occasional, Shepard and others: nukes are not the only answer. If the threatening asteroid is enough orbits away before it's calculated impact with Earth, trivial delta-V or momentum changes would add up over time to change its orbit enough to miss us. Solar-powered ion rockets and other 20th century technology could suffice to change orbits if enough lead time before predicted impact is achieved. This is why the NEO cataloguing is so crucial. If we don't detect an asteroid until it's barrelling down down on us, then we would be screwed, at least with present technology.

For example:

quote:

---

researchers have calculated that there is up to a one-in-300 possibility that Asteroid 1950 DA will slam into Earth on March 16, 2880.

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quote:

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Yes, it does no good simply to break it into fragments which all still hit the earth.

---

Tres already covered it, but just for the sake of posting I'll agree with him. We would be much better off if thousands of samll particles hit us than one large one. A rock has to be pretty fair sized to make it all the way through the atmosphere and still hit the ground with a good punch. If we pulverized the thing then
1) Many particles would probably miss the earth
and
2) those that did would be much smaller so a good portion of them would burn up in the atmosphere.
 

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Posted by ana kata (Member # 5666) on :
 
Actually, one of the things that happens is the forests all over the whole earth are set ablaze by the high temperature of the atmosphere. Breaking it into small pieces (UNLESS most of the small pieces then miss) would indeed limit the effects of blast damage at the impact site or sites, but the heat poured into the atmosphere would be the same, and so the vegetation worldwide would burst into flames just the same. The resulting soot would obscure the sunlight, and we'd have much the same resulting deep freeze. So breaking it up is only efficacious if we also blast most of the mass of it into trajectories that don't intersect the earth.

[ November 17, 2003, 11:45 AM: Message edited by: ana kata ]
 

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Posted by ana kata (Member # 5666) on :
 
There is a distinction, too, to be made in a possible moon strike. These things are not big enough to cause any gravitational influence whatsoever. We are talking mountain sized chunks. The entire mass of the planet (either the earth or the moon) is so many times in excess of that, that no gravitational perturbations are to be expected, no tidal changes, no change in orbit. If a "dinosaur-killer" sized chunk hit the moon there would be no effects on earth other than some very cool celestial fireworks to look at, and probably a nice meteor shower such as we get with the perseids or leonids every year.

It's the atmosphere that is primarily disturbed here on earth, and the ocean. That and an impact crater is generated at the impact site. None of those things are a problem on the moon, or not until we have bases there.
 

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Posted by Noemon (Member # 1115) on :
 
I was wondering...

Why is it, since the moon has been bombarded all sizes of space debris since time out of mind, that it doesn't already have lots of good nickel-iron deposits? Is it possible that it does, but that we just haven't looked deep enough for them?
 

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Posted by ana kata (Member # 5666) on :
 
Hey, that IS a thought. Some of the impactors, at least, can be expected to have been the standard nickle-iron sort of asteroidal material. We haven't taken samples but from a few places. I bet there's really plenty already there for what we need, even if we haven't found it yet. <laughs> Good thinking, Noemon!
 

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Posted by eslaine (Member # 5433) on :
 
The entire visible side of the moon (the one that faces us) is composed of denser materials than the other half. This is likely due to the Mare Imbrium impact, which made the surface in that part of the Moon molten. There is likely all kinds of cool dense materials like that from those massive impacts.

To say that an asteroid impact on the Moon would not affect the Earth, would be rather presumtuous until we actually see an event. The impacts that created the lunar seas probably did have affects on our own planet.

But there is no way for us to know for sure. Not yet anyway.
 

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Posted by Noemon (Member # 1115) on :
 
::preens::
 

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Posted by Dan_raven (Member # 3383) on :
 
Here is a threat analysis for you.

If we can build a platform to effect the courses of larger Asteroids and comets in NEO, what is to stop such a platform from either directing such object to earth, or to be aimed at earth, in stupid misguided attempts to destroy one enemy or another.

In other words, is humanity in greater danger of being wiped out by one of these objects, or by the misuse of the technology that could save us?
 

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Posted by eslaine (Member # 5433) on :
 
Some great SF has already been written about that. Walter John Williams has mentioned it more than once.

There is a great Corporate card in the CCG Netrunner called I Got A Rock. If the corp. gets this card out, it will probably win (for fans of the game, the card does 15 meat damage to the hacker). Someone hacks your net? Express your deep dissatisfaction with asteriods!

But the idea that we can do this to asteroids highlights a real 'double-edged' problem. Anything travelling fast enough is deadly. Propulsion technology is a reaction to this (pun intended). We are researching how to get things travelling very quickly, hopefully very cheaply. You could de-orbit a schoolbus into a space-station with vaporizing effects, no problem.

Nothing comes for free....
 

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Posted by ana kata (Member # 5666) on :
 
eslaine, there was just an article in Scientific American about the moon. They said nobody understood why the near side of the moon is all melted looking (covered with lava flows) compared to the far side. They mentioned speculation about it being some weird sort of tidal effect. I had not heard the theory that it was impacts, but that's interesting. Just that it happened about 4 billion years ago.

The K-T object (the dinosaur killer) was thought to have been about 6 km in diameter, I believe. (I will check this.) If an object that size hit the moon, there would be some meteors on earth from junk ejected and splash effects and stuff. Little junk. Not big stuff. Gravitational and tidal effects wouldn't happen. As for lava flows, there isn't any molton core any longer to the moon. It's solid all through, with no active "selenology" anymore. No "moonquakes", no plate tectonics, etc. Anything that flows now will have to have been melted in the impact.

[ November 17, 2003, 04:32 PM: Message edited by: ana kata ]
 

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Posted by The Rabbit (Member # 671) on :
 
What if we created a remotely operated version of the Dyson space craft. The craft could be launched using convension technology and piloted from earth using the technology used for Mars landing craft. It could then attach itself to the astroid and begin the nuclear propultion phase.
 

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Posted by Maccabeus (Member # 3051) on :
 
Say...I've been thinking about nickel-iron asteroids lately and wondering. Aren't those metals the two easiest to magnetize, or something like that?

Is the Earth's magnetic field strong enough to actually attract the things?
 

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Posted by Morbo (Member # 5309) on :
 
Macc, no, gravity is far and away the predominant force involved.
 

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Posted by Maccabeus (Member # 3051) on :
 
Whew. I figured that was how it was, Morbo, but I didn't know for sure.
 

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Posted by Caleb Varns (Member # 946) on :
 
If we developed the kind of rocket-power technology necessary to pull it off, could we construct a giant titanium net to catch them with?

Yes, I'm serious.

The wires of the net would be so thin that you couldn't see it from this far away--of course it wouldn't need to be deployed very often, I guess--but if it were sufficiently large enough and you attached enough rockets to it all around the edges, you could CATCH one, couldn't you?

With sufficient warning you could meet the object at it's own pace, and then slow it down over a long period of time (how do you power the rockets? Solar power? Fusion?) you could actually bring it safely back and HARVEST the thing. How could would that be?

Plus, a titanium net would be a really excellent weapon to use against an alien invasion. If it was large and fast enough it could do a lot of damage to a fleet--or seriously annoy one big mothership. And they could shoot holes in the net but if it was a good enough net with thin enough strings--and frickin' huge surface area--it would be really hard to totally destroy it.

I wonder if the planet has enough titanium in it...
 

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Posted by Noemon (Member # 1115) on :
 
It's looking likely that the great Permian extinction was caused by a collision with a huge space object as well.

I wonder what the dominant life form would have been if that impact and the later dinosaur killer hadn't struck the planet. Would there be a lifeform with an intelligence level equal to or even superior to our own? Would they be tool users?

Hell, for all we know, there could have been just such a being back then; that's long enough ago that any trace of their civilization would probably have been wiped out by now. Or would it? What do you think? If something like that had smacked into the Earth prior to the industrial revolution, how much evidence would there be of human civilization 251 million years later? How about if something like this struck now? What would be left in 251 million years?
 

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Posted by ana kata (Member # 5666) on :
 
Yes, I expect there would be no trace remaining of human technology after 250 million years. What could possibly last that long? Perhaps shaped stone that was then buried and never unearthed for that long? I'm not sure. Certainly nothing less durable than stone, and nothing aboveground. The pyramids are quite weathered after only, what? 7,500 years? <just guessing; I'm dreadful at history; someone who knows please say>

So there could well have been some spacefaring species on earth before the great Permian extinction. They didn't mount an asteroid defense in time. Too bad.

Actually, I believe the propensity to build things like radio telescopes and spaceships may not be a feature of any other species in our galaxy. It may be as uniquely human as, say, an elephant's trunk is uniquely elephantine. Maybe intelligence is more commonly like that of the dolphins. I would not be surprised at all. I am rather inclined to believe that's true, in fact. There is no inevitable ladder of evolution that leads to us. We are just one twig on the end of the bush of life on earth. Evolutionary pathways are very contingent on particular histories. Had the K-T impactor missed, we would certainly not be here.
 

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Posted by eslaine (Member # 5433) on :
 
The K-T event pales in comparison to another impact that we witnessed recently: Shoemaker-Levy 9.

Rocks really do fall from the skies. Ice too.
 

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Posted by ana kata (Member # 5666) on :
 
Yes, watching that in the telescope (all we actually saw were some dark smudges on the face of Jupiter, but knowing how BIG they were...) well, it made quite an impression on me, for sure.

Erik, did you follow the link to the time lapse series of the impact that I linked to above? It is VERY impressive! Particularly when viewed at double size.

[ November 21, 2003, 11:17 PM: Message edited by: ana kata ]
 

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Posted by Morbo (Member # 5309) on :
 

quote:

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How about if something like this struck now? What would be left in 251 million years?

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Noemon. Someone has pointed out the durability of stone. And fired ceramics like porcelain are remarkably durable.

So, jumbles of stone from crappy neo-classical government buildings, uncomfortable and poorly designed bathtubs, and lo-flo toilets??

I imagine any future aliens digging through our ruins would not be too impressed with our engineering skills.
 

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Posted by ana kata (Member # 5666) on :
 
The Permian extinction was indeed the mother of all mass extinctions. Each of the geologic periods represents an abrupt shift in flora and fauna, though. It's quite possible that all of them were caused by impacts of differing (but definitely large) maginitudes. We are just now (in the last decade or so) beginning to realize how very often this happens in our solar system. We definitely need to do something about it soon. The sooner the better.

You guys are going to be so mad at me for not convincing you of this sooner, if we find one headed straight down our throats and we've dilly-dallied around until it's too late. What would life be like if we were all waiting around to die, I wonder? I don't much think I want to find out.
 

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Posted by deerpark27 (Member # 2787) on :
 
Dear Friend,
I am a former genral in the Canadian Armed forces, eh, who has escaped the recent conflicts with two hundreds million dollars (Cdn) and twelve Skyhawk helicopters--I am at present sitting in one, the other eleven have been stored in Newfundland--the bombs are falling now. I need a secured bank account in a developed nation in which to deposit this money (and some safety-deposit boxes for the Skyhawks). If you will only--wjhat is that smoke coming out of the turret?--if you will, dear friend, only respond with your persoanl account number I will condider sharing 1% (Cdn) of this koney with you. That is.......200 dollars (Cdn), for only your secured bank account number (and the safety-deposit boxes)--is that oil pressure gauge correct?--then fix it you fool!, eh. I eagerly await your prompt response--Mayday!
Genral Lance "Contiki" Bay
 

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Posted by prolixshore (Member # 4496) on :
 
Well, if ya gotta go, i figure a giant asteroid to the head is one of the better ways. Plus the whole forests of the earth suddenly combusting amuses me. What a great bonfire.

See, the way I figure, if there's a giant asteroid coming to kill us all, we might as well let it. nature put a lot of hard work into that and we wouldn't want to see it all go to waste.

--ApostleRadio
 

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Posted by Maccabeus (Member # 3051) on :
 
Ana Kata, it might make us think about what's really important in life.

Funny, you know...we really are all waiting around to die.
 

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Posted by prolixshore (Member # 4496) on :
 
Kill 'em all and let god sort 'em out.


 

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Posted by ana kata (Member # 5666) on :
 
There's a freight train bearing down on you. Do you 1) Step out of the way? 2) Stay where you are and think about what's really important in life?

It astonishes me that so many people with whom I seem to share a species, seem to pick 2. <laughs>

[ November 22, 2003, 10:07 AM: Message edited by: ana kata ]
 

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Posted by eslaine (Member # 5433) on :
 
We should get together and purchase that space mission. Then we can....

Uh.... I guess we need to plan more than that.

Nearly off-subject, have you seen the Anime series Mighty Space Miners? Apart from having one of the worst titles ever, it's a pretty cool tale of disaster on the captured Haley's Comet. Lots of microgravity stuff, portrayed pretty accurately. I could only ever find the first episode though. I drag it out occasionally for some of the really pretty animation.

(the bandwidth on this machine won't allow me to load the animation mentioned above )
 

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Posted by prolixshore (Member # 4496) on :
 
Even more amazing ak, is that there was a report in yesterdays paper about how many students are injured by trains each year on this campus. 5 train tracks run through campus and the station is right down the road so they are always moving slowly. Apparently many students decide to walk across the tracks despite the fact that a moving train is 2 inches in front of them, they figure they can climb over between cars.

Also, you know I'm only kidding about the letting the asteroid hit us stuff right?

Or maybe that's just the musician side of me being irresponsible again?

--ApostleRadio
 

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Posted by ana kata (Member # 5666) on :
 
<laughs>

It's my job to watch out for icebergs and steer us clear. Your job is to play "Nearer My God to Thee" as the boat sinks.

[ November 22, 2003, 11:06 AM: Message edited by: ana kata ]
 

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Posted by Noemon (Member # 1115) on :
 
I was reading this article in New Scientist about a new type of ion engine that's been developed. The article mentioned that Japan has an asteroid chasing craft that uses this type of engine, but unfortunately the link that discussed it seems to be broken. Anybody know anything about the Japanese ship? Could something like it be modified so that it would not only chase asteroids, but actually catch them, anchor to them, and then use the ion engine to redirect the asteroid into a harmless path?

[ November 25, 2003, 01:54 PM: Message edited by: Noemon ]
 

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Posted by ana kata (Member # 5666) on :
 
That is so cool! Yes, the ion propulsion system is the definite choice for catching asteroids and directing them away from earth when we have many years advance warning. This is the approach the British team is working on as well. Even tiny course changes add up to a big difference in trajectory, given many years over which to work. I am fairly confident that, given 25 or 30 years notice, we can deal with the thing in this way or some other doable way.

We also definitely need something to handle the ones for which we get no lead time, or very little lead time. The majority of the really near misses in the last few years have been detected for the first time on the way OUT. We need better more thorough scanning, to catch these when they are inbound instead, and then we need a way to launch and obliterate them or blast them way off course within weeks or days rather than years.
 

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Posted by Noemon (Member # 1115) on :
 
Can you think of any way to obliterate them, when they're that close to Earth, in a way that wouldn't result in equal devistation? Diversion still seems like it would be the best plan, although I realize that it would take a lot more force for that to be an effective response to a threat at such close range.

The frustrating thing about this is that the ability to develop a program to protect us from threats like this is well within out technical abilities. The only thing we're lacking is the common sense to devote sufficient resources to such a program.
 

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Posted by Tresopax (Member # 1063) on :
 
That would have to be a very strong engine. Asteroids have a lot of momentum.

And about something earlier...

quote:

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Actually, one of the things that happens is the forests all over the whole earth are set ablaze by the high temperature of the atmosphere. Breaking it into small pieces (UNLESS most of the small pieces then miss) would indeed limit the effects of blast damage at the impact site or sites, but the heat poured into the atmosphere would be the same, and so the vegetation worldwide would burst into flames just the same.

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quote:

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We're talking about hundreds of billions of dollars to do what? Stop an asteroid that may or may not show up.

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Spektyr.
No, you are talking about hundreds of billions of dollars.

I along with many astronomers and scientists are asking for more telescope time for NEO (near earth objects) searches and cataloging, more telescopes optimized for such searches, and modest research into alternate propulsion (which has alternate uses for manned and unmanned spaceflight.)

I'm not sure what Ana=AK is supporting, I don't what to speak for her, she may wish to go farther than what I've just mentioned.

I agree, hundreds of billions to prevent an asteroid collision that may or may not happen is political suicide for a politician to bring to Congress.

But if one were shown to be barreling down on us, such a program would recieve enthusiastic support.

You're probabilistic arguments are unconvincing to me. At a minimum we need a more extensive NEO search--that's the first priority, so we can have early warning and time to react to a hypothetical dinosaur-killer. The international budget for such a search is currently a joke.

As far as the God argument, you yourself say " by and large people believe that we won't be tested beyond our ability to respond," Spektyr.
Sitting in our hands with confidence is hardly what I would call using our abilities to respond. Perhaps it is part of God's plan that we are tested by a huge asteroid, who can say??
 

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Posted by Spektyr (Member # 5954) on :
 
I agree that increasing the budget for early warning of NEO's is prudent. Ana has not given any indication that she feels this is anything near enough.

Personally I think that we should be looking much more extensively out into space, both in the terms of vigilence and in terms of getting a more significant manned presence outside Earth's atmosphere. The more experience we have in each category the better prepared we are to undertake the dubious task of trying to move, deflect or destroy a celestial object. Eventually this will become necessary.

As far as the religious point goes it depends largely on individual belief and the point I was trying to make was the same as the previous points in that argument: it is virtually impossible to get enough people to agree without any tangible proof. Some people may believe that God expects us to do all the work ourselves. Some believe that God will never permit a global destruction to become immenent if we are not prepared to avoid it. I personally believe that there will never be a global-killer asteroid impact because it is my belief that God will not destroy the Earth. Whether that means that such an asteroid will never be on an intercept course or that it won't happen until we have the technology to prevent it, I don't know. The point is that for me there is no sleepless nights worrying about the destruction of the human race because I have faith in God.

I'm not alone in this.

Sure, it's not a bad idea to put more money into astronomer's pockets, asking them to watch the skies more carefully. It's not a bad idea to develop better technologies for moving personelle and materials into and out of Earth orbit.

Trying to invoke terror in order to push forward one's own belief that statistically the sky is about to fall (or be blown off by an asteroid) - that is a bad idea in my opinion.

[ November 26, 2003, 01:20 AM: Message edited by: Spektyr ]
 

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Posted by ana kata (Member # 5666) on :
 
Terror? I'd be happy if I could get anyone to acknowledge that yes it's a solvable problem and we need to address it. I've seen all sorts of reactions in my 4 years of proselytizing for an asteroid defense, from "ho hum" to "you must be nuts", to "we shouldn't try to subvert God's will", but I've yet to get anything even approaching mild alarm. <laughs>
 

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Posted by Morbo (Member # 5309) on :
 
Forgot to say welcome to the forum, Spektyr.

Ok, we agree on increasing funds for the NEO search. Cool.
And an increasing human presence in cis-Lunar space, which would have numerous unrelated benefits.

I partially agree on the God question regarding this issue--some would feel fatalistic, some would agree with you that God wouldn't destroy the Earth (but not Christians), and some would feel that God would want us to save ourselves with the tools at hand, ie our present technology.

I don't think ak's motive is invoking terror, just fighting the inevitable apathy such an eye-glazing topic as statistical modeling of NEO collisions by talking about the jackpot--a collision. And she has mentioned both the stats and consequences of a major collision in an attempt to be balenced. Also, regardless of the odds of a global-killer asteroid, if one is on a collision course, it would be the worst disaster in over 10,000 years of recorded history, not counting the geological record. The subject is inherently terror-inducing.

Could you criticise a cancer or AIDS research fund-raiser for invoking terror, if she was using honest mortality and morbidity statistics of the diseases at hand?
 

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Posted by Spektyr (Member # 5954) on :
 
Perhaps it's only my perception of the way she's presented the information - I could certainly be flawed in my viewpoint. But it does seem to be strongly comprised of sensationalism.

Giving the odds of death by meteor strike - inaccurate for the topic as this figure is based on non-global-killer meteors. It's essentially impossible to give accurate odds without data about how often it has happened, how many there are, and so on.

Now don't get me wrong - I'm not saying that without this data it is more or less likely for such a strike to occur. The odds of something happening are entirely independant from our ability to do the math.

Since as you've said the most effective way to get people "awake" to the possible problem is to get them to fear it, fear tactics are certainly a viable option.

My point is that even that tact won't work. Even if you could calmly get the entire world to look at the data and agree that statistically speaking the problem does exist and should be dealt with, it won't acheive the goal. Why? Because no one wants to pay for it. Doing the end job would cost an enormous amount of money, none of which exists in any government budget without serious cuts to other things or without significant increases in tax rates. It's money no one wants taken out of their paycheck.

So instead of focusing on getting the asteroid-killer gun (or whatever) built, it makes better sense to focusing on getting the foundation for it laid.

Getting better NEO detection. Getting a better space program. In short, getting the eyes, ears, and bodies of the human race more effectively and efficiently into space. If there were hundreds of astronauts in space at any given time and we reduced the cost of moving men and women and the things they need to live in and out of space, then the prospect of moving a powerful weapon or engine far away from the Earth's solar orbit would not only be more feasible, but more politically and socially palatable.

Our space program hasn't proven it can reliably put a machine on Mars - arguably a very easy target to hit in celestial terms. Is it surprising that people are wary about spending their hard-earned money on the idea of building a device that's supposed to hit an object a mere 5 miles or so in diameter?

Get the programs going to build the space program up, refine the skills and science of putting things into space. Killing asteroids is the goal, don't focus so all-consumingly on that. Work on the in-between steps - the steps that seem more easily acheivable and affordable.

Heck, if we started working on Lunar colonies there would be a very real focus on asteroid collision avoidance. Those colonies have no protection against asteroids of any kind - no atmosphere. They would actually provide an amazing test-bed for the anti-global-killer device we'd need to protect Earth. By working on the smaller rocks we'd have more information about what is needed to stop the big ones.

While it's important to know what your intended end result is, often times the best results are found by temporarily ignoring it and focusing on the individual steps. To use OSC's books as an example - Peter didn't start posting on the net that he thought he should rule the world. He never would have gotten there if he did that. Instead he focused on the individual steps he needed to take to reach the goal.
 

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Posted by ana kata (Member # 5666) on :
 
I am certainly not fear mongering, for any reason whatsoever. I am trying to warn people of the existence of a very real threat, which has only come to the attention of scientists in the past 10 or 15 years. The 1 in 5000 (by some calculations) to 1 in 25,000 (the very lowest anyone comes up with by using extremely conservative figures) chance of any individual being killed by an asteroid strike factors in both the large and the small strikes. The large strikes are the ones that, rare as they are, actually put the probability of death up as high as it is. The reason for this is that they kill everybody. Meaning every single last person alive. Also, incidentally, all the cows, pigs, rabbits, birds, moose, deer, tigers, horses, elephants, etc. etc. All the species we love.

Okay, now the way these things usually work is that even if individual risk is higher, large catastrophes get more public attention and effort to prevent than small ones. The classic example is automobile crash deaths vs. those for commercial airlines. Even though your chance of dying in a commercial airliner is far less, when a crash occurs, more people die at once, so it's a bigger tragedy, so we work a lot harder to prevent it.

If that holds true for asteroid impact, we should be devoting far MORE resources to preventing this than to air safety, which causes about the same average number of deaths per year (in the ballpark) but far fewer AT A TIME. Instead, we are spending far LESS.

And in my own feelings, too, I find that a tragedy in which even hundreds of millions of people die is a far smaller tragedy than one in which our entire species is wiped out at a single blow. The first one is tragic, but at least there will be someone to remember how tragic it was. At least there will be stories told, again, and songs sung, and symphonies composed. After a big asteroid strike.... nothing. That is far more tragic than any smaller catastrophe.

Also, this is entirely preventable. We have the technology to do this, or very close. Only a few years or decades of developmental work would it take to be safe from these forever. We really really ought to do it. If we wait until it's too late, we will have no excuse. We will have to say our own stupidity is why we are going to all die. I just have this belief that my species is not that stupid. <laughs> I'm not sure on what that belief is based, but I cling to it.

[ November 26, 2003, 02:52 AM: Message edited by: ana kata ]
 

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Posted by ana kata (Member # 5666) on :
 
Tresopax, you say that the whole world's forests can't burn at once? On what do you base that? In fact, that's pretty much what they believe happened when the one that killed the dinosaurs hit. They found a whole layer of soot particles like the kind left behind by fires, only it's nearly everywhere all over the earth. There's a map in the article in SciAm that shows how much of the world's forests caught fire. It's most of it. This map represents, again, one model, depending on exactly how much stuff was blown back up into space, etc., and this was the most conservative one. Other models had shown much more of the world was burned. And the K-T impactor was small compared to some of them. The one that ended the Permian would have been a lot bigger.

In mill safety we say "Close calls mean something is wrong. Fix the problem before the real one occurs." The same is true in everything. We see that it's happened here in the past. We saw it happen a few years back to Jupiter while we were watching. Since then we've seen several of them whiz by very close to the earth. Close calls mean something needs to be done differently. We need to look again and figure out what. We need to fix this problem.
 

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Posted by Spektyr (Member # 5954) on :
 
But why are you trying to stir up some sense that the race as a whole is aware of the problem and is taking steps, as a whole, to fix it?

Why does it matter that everyone believes the same way you do about this particular problem, especially if it's easier to lead them to the solution instead of trying to make them believe in the problem and thereby the solution?

Set the clock back a few hundred years. Claiming the Earth was round was likely to earn nothing but ridicule, hate, and probably even "vigorous censorship" by the church.

What was to be gained by trying to cram the truth down the throats of the people, especially if you could gradually feed them the math, bit by bit until it became obvious to everyone that the Earth could be nothing but round?

(I'm not saying that's the way it happened, just giving a hypothetical situation.)

An asteroid killing device (or an asteroid deflecting device) is not a singular piece of technology. It's not some magical machine for which there is no other purpose and is built from no existing concepts.

First we need better monitoring of NEO's. Who gives a flying rip if we can blast an asteroid no one can see?

Next we need reliable vehicles to deliver the payload - whatever it may be - to a distant location with extreme precision. Sure, we can put a bomb through an Iraqi window, but these are two very different things.

Finally we need something of much greater destructive power than a three-stage nuclear device, or of far greater thrust than any current rocket engine (or greater endurance, either way). In effect, we need a solution to move or destroy an asteroid.

These are three things we don't have that at a minimum must exist to stop an asteroid from hitting the Earth (assuming a conventional approach to the problem). Two of the three things are important for the space program as it is.

So why is your focus on getting the end product instead of advancing the platform for the two things that we still don't have, have many uses for, and can be much more easily supported by the human race as a whole? Once we've got those parts, the third wouldn't seem all that hard to do. Nor would it seem particularly expensive.

On one hand you've got "The sky is falling! Quick, give me 100 billion dollars to hold it up!"

On the other you've got "Hey, let's spend 25 billion to learn more about the heavens, and another 25 billion to study ways to get there safer, more efficiently, and more effectively." And then a couple years later when that's done, "By the way, using the current detection system and that new rocket sled we could build us a tool for stopping asteroids for a mere 50 billion."

It's Las Vegas baby. While you're focus on how good the entertainment is and how cheap the food and hotels are, they're draining your wallets at the table. Not exactly the same concept, but the basis is there.

If one approach isn't working, you've got the people looking at the wrong thing.

A Yugo salesman doesn't expound on the differences between his product and a new Mercedes Benz. He focuses on the economy of his product.

Divide the concept up into more popular and more digestible parts. It's not like you're lying to people to get some evil plan to fruition. You're leading a herd of stubborn donkeys to water by letting them think they're not being driven.
 

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Posted by eslaine (Member # 5433) on :
 
*adulates ak for creating a great thread to read!*

There's not enough science threads here lately.

Thanks everyone.
 

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Posted by Tresopax (Member # 1063) on :
 

quote:

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Tresopax, you say that the whole world's forests can't burn at once? On what do you base that? In fact, that's pretty much what they believe happened when the one that killed the dinosaurs hit. They found a whole layer of soot particles like the kind left behind by fires, only it's nearly everywhere all over the earth. There's a map in the article in SciAm that shows how much of the world's forests caught fire. It's most of it. This map represents, again, one model, depending on exactly how much stuff was blown back up into space, etc., and this was the most conservative one. Other models had shown much more of the world was burned.

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quote:

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As it hit, the asteroid or comet disintegrated and vaporized a chunk of Earth's crust, creating a plume of debris. WIth increasing speed, the fiery plume rose out of the crater and rocketed through the atmosphere, carrying crystals of quartz that, only moments before, had been as deep as 10 kilometers below the surface.

The plume swelled to a diameter of 100 to 200 kilometers, punching its way into space and expanding until it enveloped the entire Earth. Material then began to fall back under the influence of gravity, plowing into the atmosphere with nearly all the energy with which it had been launched from Chicxulub [the impact site]. Moving at speeds of 7,000 to 40,000 kilometers an hour, the particles lit up the sky like trillions of meteors and heated a large volume of the atmosphere to several hundred degrees, before slowly settling to the ground and forming the layer we see today.

Melosh's team calculated that the reentering debris could have ignited vegetation over a huge fraction of the globe. But nobody in 1990 knew the location or precise size of the impact, so the team could not determine the total amount of heating or the distribution of the fires. Although soot had been found throughout the world, fires need not have erupted everywhere, becasue soot could have been blown to some sites by the wind.

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quote:

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To dry out plants and set them on fire takes 12,500 watts of heating per square meter for at least 20 minutes. These conditions were reached in two main areas, centered on Chicxulub and its antipode in India. From these regions, corridors of fire stretched westward as Earth rotated beneath the hail of reentereing debris. This computer simulation [showing the burning covering about half the landmass of the world outside the arctic areas] assumes a certain impact configuration; other scenarios incinerated even larger areas.

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quote:

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Nearly all of that energy ends up as heat in the atmosphere.

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quote:

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In 1990 University of Arizona planetary scientist H. Jay Melosh and his colleages described how an impact could have set off fires around the world.

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Unfortunately, the whole article isn't online. You can download it for a charge. I am typing this stuff in from my print copy. <quaint, neh?>

[ November 26, 2003, 04:53 PM: Message edited by: ana kata ]
 

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Posted by BannaOj (Member # 3206) on :
 
Try here. I'm sure you'll find other interesting stuff too. And yes it is the same Jay Melosh. He is my friend's PhD advisor, though her name isn't up on his site yet since she recently changed advisors.

http://www.lpl.arizona.edu/~jmelosh/melosh2.html

AJ

[ November 26, 2003, 04:56 PM: Message edited by: BannaOj ]
 

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Posted by ana kata (Member # 5666) on :
 
By the way, let me put in a plug here for Scientific American. It's absolutely my favorite magazine ever. I've been reading it since the 60s. It's much more readable and accesible to the layman than, say, Nature, who will discuss hymenoptera for a whole page and never tell you they mean bees and ants. Scientific American is not dumbed down at all, but it's accessible. They will say (the order of insects which includes bees and ants) the first time they use the word hymenoptera in an article, for instance.

I started out for the physics and astronomy and math articles, but gradually I read more and more of the biological ones (cause biology has been so hot during all these last decades) until I was fully up to speed. Now I try to read it all, cover to cover, every month.

Isaac Asimov made the same discovery, I found out. He read the whole issue every month for many years of his life too. He was sort of the dude who taught me about science so I grinned when I read that. Martin Gardner introduced me to many ideas of game theory, number theory and other cool stuff like that. It's just a great magazine. I have to rave about it sometimes.
 

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Posted by ana kata (Member # 5666) on :
 
Oh yes, AJ, that's a good link! He's got some great stuff there about impact studies.

Looks like he also was involved in the understanding which we've really just recently come to that the moon was formed from the collision of a Mars sized body with the proto Earth. We've always known the Moon was a weird sattelite. It's way too big, almost a binary planet with us. But only in the past, I dunno, six year or so have they come to understand how it must have come about.
 

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Posted by Chaeron (Member # 744) on :
 
Has the 536 AD event been mentioned yet? I think it is the clearest example of a truly disasterous impact in recorded history.
 

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Posted by Spektyr (Member # 5954) on :
 
Okay, short post this time.

Ana - stay on target with me here. You have expressed exasperation because "Four years later - still no asteroid defense project". I'm assuming you've either got a job where you feel you have influence over this sort of thing or you've been spearheading a grass roots campaign for this development. Apparently it isn't working and you're frustrated about that.

So why is it that every time I ask you why you haven't changed tactics you answer back with another explanation of your current tactics? Why not change course if you've spent four years going that direction and not achieved the goal?

One other thing I wanted to point out: the Jupiter strike. First, Jupiter is obscenely bigger than the Earth, and therefore astronomically more likely to be hit by an asteroid than us. It's like firing a tennis ball launcher into a parking lot. Is the ball more likely to hit the skateboard or the charter bus? Second, it's a gas giant so an asteroid impact means something very different for Jupiter. Without a better understanding of exactly what is beneath the clouds it's hard to compare the visual record of that asteroid strike to what we think would happen on this planet in similar circumstances.
 

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Posted by Noemon (Member # 1115) on :
 

quote:

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The scientific community hasn't even been able to accurately predict the influence of increased CO2 levels 10 years in advance. I'm certainly not going to believe they can accurately predict what effect an asteroid striking had millions of years ago, without ever seeing any asteroid of anywhere near that size strike the earth, based solely on hypothetical models and soot samples.

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Tres, it seems to me that your argument is basically "I don't believe it, and nothing you say is going to change my mind". Is that the case? Is there anything, short of an asteroid slamming into Earth and causing a repeat of the two known asteroid-caused mass extinctions, that would convince you of the possibility of this?
 

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Posted by ana kata (Member # 5666) on :
 
Chaeron, I just looked up the 536 AD event after your post. I had not been aware of that one. They know about it from tree ring evidence. It's quite interesting and also had global effects, it seems.

I also came across something that mentioned that if the Tunguska event of 1905 had hit New York City instead of a remote part of Siberia, that millions of people would have died from that one. It certainly gives you something to think about.

[ December 01, 2003, 09:52 AM: Message edited by: ana kata ]
 

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Posted by Noemon (Member # 1115) on :
 
Sunlight's Impact on Asteroid Trajectory (and, incidentally, a really cool way of determining an asteroid's mass).
 

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Posted by eslaine (Member # 5433) on :
 
The thread that keeps on giving. Thanks guys.
 

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Posted by Noemon (Member # 1115) on :
 
::tips hat::
 

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Posted by Noemon (Member # 1115) on :
 
Well, there's a new paper out that supports Tres' skepticism about an asteroid impact igniting a global firestorm.
 

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Posted by ana kata (Member # 5666) on :
 
Interesting. I almost missed this latest! The jury is still out, it seems, on the global wildfires. This is the first time I've heard 1000 degrees C, though! That would sterilize the place, wouldn't it? I heard hundreds of degrees F. Some say 400, some as high as 700. The Scientific American article said only "hundreds". This is really interesting.

For the purpose of the question at hand, I suppose it doesn't really matter how exactly an asteroid impact kills off species. But I still would like to know.
 

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Posted by Noemon (Member # 1115) on :
 
Planetary Defense Forum

Wish I had the time and money to attend this.
 

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Posted by aka (Member # 139) on :
 
Yes! It's at least comforting to see that someone besides me is thinking about these things. I hope we get a detailed report of what the conference comes up with, if anything.
 

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Posted by Noemon (Member # 1115) on :
 
Whew!
 

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Posted by Han (Member # 2685) on :
 
Tyler Cowen of the Volokh Conspiracy endorses an asteroid defense project.
 

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Posted by aka (Member # 139) on :
 
Sheesh! That was scary, Noemon! I'm glad I didn't know about it until it was already past.
 

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Posted by Da_Goat (Member # 5529) on :
 
Off-topic: Did anybody else think this was going to be a quirky Landmark thread, judging from the title?
 

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Posted by Zalmoxis (Member # 2327) on :
 
Greg Easterbook is also on board with the idea and thinks NASA should do it.

EDIT: that should be Easterbrook.

[ February 27, 2004, 04:01 PM: Message edited by: Zalmoxis ]
 

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Posted by Farmgirl (Member # 5567) on :
 
Thought I would resurrect this thread by Ana Kata in honor of Today's CNN Report

quote:

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Dangerous space rocks under watch
Asteroid protection plan proposed

A large asteroid survey is nearing completion.

WASHINGTON (Reuters) -- They are out there, ready to smack into the Earth and wipe out human civilization, but astronomers said on Wednesday they are well on their way to finding every asteroid that poses a threat.

The next task will be to look for smaller objects that might just destroy, say, a city, the experts told the U.S. Senate's Subcommittee on Science, Technology and Space.......

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Farmgirl
 

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Posted by Shigosei (Member # 3831) on :
 
Looks like OSC is advocating that we construct a system to stop meteor impacts. No suggestions on how to do it, just that we should.
 

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Posted by ak (Member # 90) on :
 
It was 1999AN10, the one that made me realize what we should do. Now, five years later, finally some things are starting to stir around about this.

Will be very nice when one of you is president and I can just say, "hey, we need an asteroid defense!" and it will be done. You guys get busy on that, okay? I'm not one who can convince people and get huge movements going. I just can see what we need to do. The rest must be up to ye other jatraqueros.

[ September 07, 2004, 03:05 PM: Message edited by: ak ]
 

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Posted by KarlEd (Member # 571) on :
 
Make me President and I'll institute one.

(See, I think I'm up to the job of being President. I'm just not up to the job of campaigning to be President.)
 

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Posted by PSI Teleport (Member # 5545) on :
 
Now there's a good platform.

You can say, "Not only is my opponent ill-equipped to deal with our asteroid threat, he refuses to believe it even exists!"

Keep saying that and you'll be hired. : )
 

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Posted by LockeTreaty (Member # 5627) on :
 
After seeing all those movies where asteriods roughly the size of the moon come hurdling towards Earth to kill all life on the planet, I have finally come up with a suitable solution. My solution doesn't call for finese. There will be no drill team that will lower a bomb deep into the crust of the asteroid. No my method is much simpler. We grab any asteriods that come by Earth with manned shuttles or some sort of machine that can slow down the asteroid. Then we graft all of our asteroids together into one big hunk of asteroid. We finish the project by installing an engine on one end of the hunk of rock and a camera on the other end. Then when ever an asteroid that will certainly strike Earth comes by we send our huge hunk of mobile rock at a collision course with the incoming asteroid. This would either change its trajectory or result in a break up of the asteroid.
One question you might be asking is why the camera on one end? We can easily use satelittes to track our flying piece of rock. Who needs a camera? The answer is simple. The footage from the camera can be used in driver's ed courses. "Imagine this is you, you're drunk and somehow you don't see the 600 mile wide asteriod you are about to collide with. What kind of fool would you have had to be to get so drunk and then drive." See, by using my method we avert the end of life on the planet, plus we convince .000001% of all drunk drivers that drinking and driving is bad thing. (The whole drinking and driving bit was meant entirely in jest, my views on drinking and driving are firm in that it should never be allowed to occur. Although the diatribe was purely a joke I would surely back any plan that would stop even one drunk driver.)
The second question one might present is that it would be extremely difficult to halt an asteroid no matter what the size. My answer is this: If somehow I can control nuclear weapons with my PS2, then surely you can stop a rock from moving.

p.s.- I wrote this post after doing economics homework for about six hours straight. Thus, because of the nature of economics my sense of reality is screwed up.
 

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Posted by WishfulWiggin (Member # 6823) on :
 
LockeT, I like that idea.
But if we did have the technology to 'grab' astreroids and put them into orbit around Earth, I would personally use them as colonies. We then should be able to not hurdle those colony-laden-asteroids at another asteroid, but rather into deep space. Of course it would be hard for us to avoid this asteroid from colliding with anything else, and from the acceleration due to the 'hurdling' from killing the colonists. This is just an idea, created in the darkest parts of my brain and placed here, on Hatrack.
-Liz

[ September 07, 2004, 09:30 PM: Message edited by: WishfulWiggin ]
 

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Posted by Noemon (Member # 1115) on :
 
Target Picked for ESA Asteroid Nudging Mission
 

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Posted by Tatiana (Member # 6776) on :
 
Oh, Noemon, this is awesome! I love how they named the spacecraft, too. <laughs> So appropriate!
 

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Posted by Noemon (Member # 1115) on :
 
Isn't it great? I wish this had been done earlier, but I'm glad that someone is finally stepping up.

And yeah, I laughed aloud at the crafts' names.
 

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Posted by Shigosei (Member # 3831) on :
 
Hey, look! They named MN4 (the one they were looking at last December because they thought it might hit the earth in about 25 years) Apophis! A fitting name for a potential threat to the earth. I wonder if the astronomer was a Stargate fan, or if the name was simply picked from Egyptian mythology.
 

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Posted by Kwea (Member # 2199) on :
 
I am leaning towards mythology, they get a lot of their namess for things that way...although I would imagine NASA geeks like Stargate as well.
 

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Posted by Noemon (Member # 1115) on :
 
Proposed Gravity Tug Would Deflect Asteroids
 

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Posted by Noemon (Member # 1115) on :
 
This is a better article on the same subject
 

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Posted by Tatiana (Member # 6776) on :
 
Awesome! Pod just sent me the same link! :-)
 

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Posted by Tatiana (Member # 6776) on :
 
Here is a fantastic Astronomy Picture of the Day (APOD) showing what our neighborhood in the solar system looks like, just the ones we've identified and are tracking so far. I thought it was a great illustration of why we might want to keep our eyes peeled and develop some form of defense. Earth is on the third blue circle from the middle.

APODs are usually awesome! Click on the links at the bottom for the archive of all of them for a long time back. It's a cool site I check every day.

[ March 19, 2006, 10:45 AM: Message edited by: Tatiana ]
 

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Posted by Tatiana (Member # 6776) on :
 
ANOTHER COOL APOD animation of the asteroids in Earth's near vicinity over a two month period. All these were found within the last year, I think it said. It's a shooting gallery out there!
 

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Posted by Tatiana (Member # 6776) on :
 
Here is a very cool time lapse video of 73P / Comet Schwassmann-Wachmann 3 as it approaches earth. Don't worry, this one poses no danger to us. I just thought this video was very cool, and this seemed like the right thread in which to post it.
 

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Posted by Tatiana (Member # 6776) on :
 
My pet topic in the news again! Isn't the illustration awesome?
 

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Posted by Tatiana (Member # 6776) on :
 
By the way, it was 1999-AN10 that first got me thinking about this, as reported in the free Spanish language weekly paper given out at the local Mexican restaurants. I was puzzling out the text, and it was using words like "apocalyptico" . So it has been 7 years now. We could have made significant progress, if we had decided to make it a priority. I'm sure when we see one heading down our throats, Bush will say nobody could possibly have forseen this.
 

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Posted by Hamson (Member # 7808) on :
 
I don't find it strange as much as stupid that we're gambling our planet's entire future on the hope that we will never be hit by something of a mass-genociding size.

An Earth-shattering asteroid collision would be pretty much comparable to playing a video game for hours, and then suddenly the power goes out, and you never bothered to save it. Then you have to restart from the begining.
 

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Posted by Shigosei (Member # 3831) on :
 
I was reading the Bad Astronomy Blog (a very cool astronomy resource), and I saw a link to this incredible video of a massive asteroid impact. Fortunately, an impact of this size is incredibly unlikely. Additionally, something that size is going to be pretty visible, so if one like that were headed our way, we'd already know about it. This is very much a "what if?" scenario.

But don't worry...Japan has it all under control.
 

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Posted by Tatiana (Member # 6776) on :
 
Wow, that was really amazing! It's true that the larger the impactor, the less likely the event, but there have been near misses of 1 km in diameter since I've been keeping up with things. That one looked bigger than 1 km but much much smaller than, say, the moon. In fact, they now have good evidence showing that the moon was formed when a Mars-sized body struck the proto-Earth off center. So it may be unlikely, but it's happened before that something very much bigger than the one they showed has struck the Earth.

Anyway, there's little chance any life more complex than bacterial could survive an impact as large as the one shown. Life is just too delicate and too dependent on the atmosphere. We'd probably have to start over from bacteria after that one. Unless we avert it, of course! I hope Japan does have it under control! Surely the U.S. is dropping that very important ball!

Thanks for the links, Shigosei!
 

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Posted by Juxtapose (Member # 8837) on :
 
I thought it looked to be about 1000km across. Anyone elses opinion? Wouldn't something like that seriously crack the entire planet, alter it's orbit and revolution, things like that?

That was a really cool video, Shigosei. Thanks for posting that.
 

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Posted by Tatiana (Member # 6776) on :
 
The wave of superheated steam and magma engulfing the Himilayas was scary!

[ August 03, 2006, 09:02 PM: Message edited by: Tatiana ]
 

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Posted by Mathematician (Member # 9586) on :
 

quote:

---

Originally posted by Juxtapose:
I thought it looked to be about 1000km across. Anyone elses opinion? Wouldn't something like that seriously crack the entire planet, alter it's orbit and revolution, things like that?

That was a really cool video, Shigosei. Thanks for posting that.

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quote:

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Originally posted by Shigosei:
[QB] I was reading the Bad Astronomy Blog (a very cool astronomy resource), and I saw a link to this incredible video of a massive asteroid impact. Fortunately, an impact of this size is incredibly unlikely. Additionally, something that size is going to be pretty visible, so if one like that were headed our way, we'd already know about it. This is very much a "what if?" scenario.

Edit: By the above I mean that an asteroid impact 1,000 of that size could cause the end of human civilization. It don't take much.

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quote:

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Originally posted by Orincoro:
[In fact, no. There is a fairly good chance we would not see a meteor that was big enough to cause global devastation. We know this because we have caught glimpes of meteors big enough to cause terrible damage, only after they have passed very very close to the Earth, and are receeding-- which means we didn't see them approach. Some of these have been quite large- asteroid wise.

And BTW- a comet this big (more like a moon), hits the Earth and the tower of London survives the initial shockwave? The wind alone would take it to peices I would expect. Then there is the smaller matter of the impact having to transfer momentum into the earth, nocking it in its rotation and spewing ejector flap from the other side of the planet.... hmmm [/QB]

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quote:

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The wave of superheated steam and magma engulfing the Himilayas was scary!

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Yeah. I also thought the part where the ocean looks sort of normal and then becomes steamy and starts boiling away was chilling. Pun sort of intended.
 

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Posted by Tatiana (Member # 6776) on :
 
Mile wide chunk of rock to pass within 2,100,000 miles of earth (about as far away as the moon). If you're interested in observing it, the data is all given in the link.
 

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Posted by Launchywiggin (Member # 9116) on :
 
I think you're a couple million miles off the actual distance from the moon to the earth.

The moon is 238,857 miles from earth
 

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Posted by The Rabbit (Member # 671) on :
 
This is really cool but it should be noted that the moon is ~ 240,000 miles from the earth so this chunk of rock will be nearly 10 times further away than the moon.
 

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Posted by Tatiana (Member # 6776) on :
 
Oh, you're right! I read that as 210,000. Carry on!
 

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Posted by Tatiana (Member # 6776) on :
 
Some new info on this topic, in case anyone's interested. This is a really good article.

http://space.newscientist.com/article/dn11901-nasa-analysis-of-asteroid-risk-deeply-flawed-critics-say.html
 

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Posted by Tatiana (Member # 6776) on :
 
We might lose Arecibo which would make it harder to look for near earth objects, and potential impact threats. That's shortsighted and unfortunate.
 

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Posted by aspectre (Member # 2222) on :
 
"Go outside after sunset and face north. The green Comet Linear VZ13 is gliding through Draco a few star hops from Polaris. Too dim for naked eye, but easy to see in 7X35 binoculars." [/paraphrase]
For more info. Check out the 3D-orbit link, and play with the Java scroll bars to shift viewpoints.
Coulda been one HECKUVA space SPECTACULAR. And we just missed it.

On 15Augus2007, the Comet/2006 VZ13 (Linear) nearly passes through the point which Earth occupied on 27May2007. Since aphelion was on 7July2007, Earth was somewhat close to that apehelion (farthest distance from the Sun) of 1.01671AU on 27May2007.
CometVZ13 will cross nearly the same point at ~1.018AU from the Sun on 15August2007.

ie On 15August2007, VZ13 will come within ~0.002AU of a point that Earth occupied on 27May2007.

Another cute factoid, VZ13 will be between 1.015AU and 1.016AU from the Sun between 9August2007 and 12August2007; less than Earth's aphelion distance, but at a point above Earth's orbital plane.

Fortunately, that 2&1/2 month difference and steep orbital inclination means that the closest VZ13 will get to Earth is 0.575AU on yesterday and today.

Lest we get complacent, the 2006 in C/2006 VZ13 is the discovery year. If that Earth-crossing comet had come 2&1/2 months earlier on a slightly altered trajectory allowing intersection with Earth, there would have been nothing that we could have done about it in the time frame between discovery and impact.

Couldn't find a mass estimate, but comets tend to be large, much larger than the Earth-crossing asteroids that we've fretted about. Now consider the results of a Chicxulub-sized cratering event on our civilization.

[ July 13, 2007, 09:48 AM: Message edited by: aspectre ]
 

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Posted by Tatiana (Member # 6776) on :
 
I think on all these repeat earth-orbit-crossing bodies, we should act to neutralize the threat for the benefit of future generations. The motions of the bodies in the solar system are chaotic (in a mathematical sense) and inherently unpredictable in the long run. Any asteroid or comet that repeatedly crosses the earth's orbit is a threat from now on. We should, while we can, take those threats out. The best way would be to deflect them to impact the moon, I think. This way, they're totally gone, nothing is harmed, and we get the bonus of possible nickel-iron deposits for lunar mining down the road. Eventually when we have lunar bases and stuff we can't do this anymore. So now is the time!
 

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Posted by The Reader (Member # 3636) on :
 

quote:

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The best way would be to deflect them to impact the moon, I think. This way, they're totally gone, nothing is harmed, and we get the bonus of possible nickel-iron deposits for lunar mining down the road.

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Another bonus is the PR that could go into a Planned Lunar Impact! I'd throw a party for that.
 

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Posted by Tatiana (Member # 6776) on :
 
I know! Wouldn't it be awesome? Part of the fun would be the awesome fireworks display.
 

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Posted by The Reader (Member # 3636) on :
 
Especially on New Years Eve, during a full moon.
 

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Posted by Tatiana (Member # 6776) on :
 
There's someone else out there like me!

The B612 foundation. What a great name for it! Jeni will appreciate that, I'm sure.

quote:

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I think it's a very clear situation, not unlike Hurricane Katrina, where it's only a matter of time before this happens. It differs from Katrina because we can't accurately predict the future of a hurricane. But in this case, you can predict very precisely, and you can know decades ahead of time if there's likely going to be an impact. And you can't deflect a hurricane, all you can do is button down or evacuate.

In this case, we could literally prevent a disaster on the scale of 10,000 Katrinas. For humanity to have this capacity and not be prepared to use it is an anti-survival thing. You're rolling the dice -- you're saying, we could do something about it, but we'll take the risk of going the way of the dinosaurs. It seems to me that this is a very irresponsible act.

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quote:

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Originally posted by Tatiana:
I think on all these repeat earth-orbit-crossing bodies, we should act to neutralize the threat for the benefit of future generations. The motions of the bodies in the solar system are chaotic (in a mathematical sense) and inherently unpredictable in the long run. Any asteroid or comet that repeatedly crosses the earth's orbit is a threat from now on. We should, while we can, take those threats out. The best way would be to deflect them to impact the moon, I think. This way, they're totally gone, nothing is harmed, and we get the bonus of possible nickel-iron deposits for lunar mining down the road. Eventually when we have lunar bases and stuff we can't do this anymore. So now is the time!

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Only there are Billions of such objects in the solar system. You could mess with as many as you want and never save yourself any trouble. Besides, there are near passes from asteroids so often that we often don't even know when they're getting close, until they've already passed us.

What, can someone tell us, would be the effect of a mile wide object impacting on the moon? I speculate it would be problematic at best.
 

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Posted by The Reader (Member # 3636) on :
 
I suspect that some debris would reach Earth, causing a good meteor storm. Most of the post-impact ejecta would likely stay near the Moon, likely obliterating some existing features, and any nearby moon landing sites.

I know quite a lot about this stuff, but you'll want to ask a professional because I can't be sure.
 

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Posted by Nathan2006 (Member # 9387) on :
 
Listen, I've only read the first page... Rather, half of the first page.

Here's my problem. The chances of *one* person (Me) dying because of a meteor crash is 1 in 25,000... But what are the chances that an asteroid large enough to wipe out all of humanity will hit the Earth? Or, even half of humanity?

I'm terribly sorry if this has been addressed in all of those links and I've missed it.

*******Edit*******

Sorry, I realize now the topic has drifted.
 

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Posted by Tatiana (Member # 6776) on :
 
New scientific findings suggest that a large comet may have exploded over North America 12,900 years ago, explaining riddles that scientists have wrestled with for decades, including an abrupt cooling of much of the planet and the extinction of large mammals.

Interesting article about it here.
 

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Posted by Tatiana (Member # 6776) on :
 
Nathan, don't apologize. I'm delighted that you took an interest. I'm sorry I didn't see your question before now. The probability is low but the consequences are so great, our ability to avert the disaster is so cheap comparatively, that it makes good sense to do serious work on the problem.

For one thing, in general, we care more about larger scale disasters. We spend, for instance, many times the amount per annual death on airline safety than we do on traffic safety, because even though cars kill a whole lot more people, they kill them by ones and twos and fives. Airplane crashes tend to kill a couple of hundred at a time. This is a general rule in averting risk. Humans spend more per annual death on preventing things that kill more people at once. So asteroid impacts, which kill far more at once than airplane crashes, should be attracting more funds per annual death rather than less, as is the case. It's a simple concept but hard to put in words. Did I explain that in a way that it makes sense?

Also, we have the ability to actually do something about this threat, unlike many other threats to the planet as a whole like nearby supernovas, the sun going nova, super-volcanoes exploding, and so on. Because this would cost only a comparatively modest amount to make us safe, it makes a lot of sense for us to do this.

The rest of the arguments for why it is such a smart thing to do are on the first page or so of this thread. I hope I didn't wait too long to answer your question, Nathan. Once again, I apologize for not seeing it sooner. =)
 

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Posted by King of Men (Member # 6684) on :
 

quote:

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So asteroid impacts, which kill far more at once than airplane crashes, should be attracting more funds per annual death rather than less, as is the case.

---

quote:

---

Originally posted by Orincoro:

quote:

---

Originally posted by Tatiana:
I think on all these repeat earth-orbit-crossing bodies, we should act to neutralize the threat for the benefit of future generations. The motions of the bodies in the solar system are chaotic (in a mathematical sense) and inherently unpredictable in the long run. Any asteroid or comet that repeatedly crosses the earth's orbit is a threat from now on. We should, while we can, take those threats out. The best way would be to deflect them to impact the moon, I think. This way, they're totally gone, nothing is harmed, and we get the bonus of possible nickel-iron deposits for lunar mining down the road. Eventually when we have lunar bases and stuff we can't do this anymore. So now is the time!

---

Only there are Billions of such objects in the solar system. You could mess with as many as you want and never save yourself any trouble. Besides, there are near passes from asteroids so often that we often don't even know when they're getting close, until they've already passed us.

What, can someone tell us, would be the effect of a mile wide object impacting on the moon? I speculate it would be problematic at best.

---

There are billions of objects in the solar system, but only a small number of large repeat earth-orbit-crossing bodies. It makes sense to deal with them, because they pose the greatest risk to humanity. And the reason near passes are not noticed more is that no serious effort with large resources has been made to look for them.
 

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Posted by King of Men (Member # 6684) on :
 
Y'know, people, you probably want to be careful throwing around numbers like 'billions'. 10^9 is pretty big. If you want to say "Some large number", use 'zillions', which doesn't have any connotations of exactness; if you use 'billions', people might think you're being exact. I very strongly suspect that the number is only in the millions, at most, short of counting grains of dust. This is an important difference which is obscured by the careless use of 'billions'.
 

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Posted by Primal Curve (Member # 3587) on :
 
I really hope we get hit by an asteroid. It'll be the only way to shut you up. <stares>
 

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Posted by Tatiana (Member # 6776) on :
 
Primal, did you mean me or KOM? <asks sweetly>
 

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Posted by Primal Curve (Member # 3587) on :
 
<waits patiently for asteroid>
 

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Posted by Leonide (Member # 4157) on :
 
Seriously, Glynn? Unless you have some insult/joking relationship going on there I'm not aware of -- out of line.
 

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Posted by Tatiana (Member # 6776) on :
 
Ah, how delightful! In that case let me introduce you to a clever feature that forums like this have. See on the main page that little column headed "topic starter"? The ones that say "Tatiana" or "ana kata" or "ak" or "aka" in that column, please don't let me impose upon you ever to click on those threads. After all, your blood pressure is obviously high and your patience short. It would seem to be a great boon to your health for you to simply forbear. I promise I won't be upset in the least.
 

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Posted by Primal Curve (Member # 3587) on :
 

quote:

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Originally posted by Leonide:
Seriously, Glynn? Unless you have some insult/joking relationship going on there I'm not aware of -- out of line.

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Can I get two now? Or is that too much to ask?
 

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Posted by Tatiana (Member # 6776) on :
 
Leonide, thanks! As you see, Glynn and I don't have any relationship, joking or otherwise, he's just being his usual delightful self.
 

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Posted by Leonide (Member # 4157) on :
 
How very unChristian of you, Glynn. A militant and/or apathetic atheist like me doesn't stand a chance against your firey asteroid vengeance.
 

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Posted by Nathan2006 (Member # 9387) on :
 

quote:

---

Originally posted by Tatiana:
New scientific findings suggest that a large comet may have exploded over North America 12,900 years ago, explaining riddles that scientists have wrestled with for decades, including an abrupt cooling of much of the planet and the extinction of large mammals.

Interesting article about it here.

---

Geez, Tatiana. Everybody knows that the abrupt cooling was caused by the flood.

Duh.

Anyway...

Thanks for answering. That does make a lot of sense... So... Now what?

Do we just raise awareness? (I feel that the answer is probably in one of those links... I hate dial-up!)
 

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Posted by Tatiana (Member # 6776) on :
 
Great Britain seems to be getting out in front on this issue. I'm really glad someone's working on it.

"You could ram it hard with a one-tonne spacecraft and it would change momentum enough to shift it.

If you leave it any later you either have to use much more mass or use a nuclear bomb to achieve greater impact."
 

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Posted by Noemon (Member # 1115) on :
 
Are Mirrors the Best Way to Deflect Asteroids?
 

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Posted by aspectre (Member # 2222) on :
 
Nope. The mirrors would act as solarsails, pushing themselves away from the asteroid. So ya'd hafta have more rocket power and trajectory-control programs to keep those mirrors in place than ya would for a gravity tug.

Asteroids tumble. So focusing mirrors on a spot long enough to raise temperatures sufficiently high to cause vaporization is problematic. That or ya'd hafta have a HECKUVA LOT more mirrors than they seem to assume.
The vapor would then act as a mirror itself, greatly decreasing the rate at which asteroidal material would vaporize. If the vapor is hot enough, it'll act as a phase conjugate mirror reflecting the beams directly back into the mirrors, which would further deflect those "solarsail" mirrors.

Then the direction of thrust tumbles along with the asteroid. Which means at best chaotic thrust-vectoring pushing the asteroid in unpredictable directions.

Can't focus on a pole because asteroids tumble around more than one axis. And even if asteroids spun about one axis, unvectored thrust would cause it to begin nutating around another.
 

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Posted by mr_porteiro_head (Member # 4644) on :
 

quote:

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Can't focus on a pole because asteroids tumble around more than one axis.

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quote:

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Originally posted by Tatiana:
1 in 75 chance of a skyscraper sized asteroid hitting Mars in January. Stay tuned for more info!

It's a shooting gallery out there, y'all!

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Probability of asteroid strike has risen to 1 in 25!
 

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Posted by Tatiana (Member # 6776) on :
 
I'm so watching this one if it hits. Jupiter was amazing and cool in 1994 when Shoemaker-Levy 9 hit! Mars is so much closer! Oh I hope it won't hurt Spirit and Opportunity, though!
 

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Posted by Tatiana (Member # 6776) on :
 
By the way, Mars is about the same size planet as Earth. It's a bit closer to the asteroid belt, but otherwise, very similar to earth in all its characteristics as a target body. This should show that there's quite a good chance of these things hitting us as well, and it only makes good sense for us to begin work on a defense system (while, of course, continuing to survey the sky for possible impacting bodies). Had we begun in 1999, when I first started talking about it, we could be nearly ready by now. As it is, we have no idea when we're going to need it. Let's get going on it right away.

[ December 31, 2007, 11:51 PM: Message edited by: Tatiana ]
 

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Posted by Starsnuffer (Member # 8116) on :
 
Actually, Mars's radius is .533 that of Earth's radius. Making it nearly half Earth's size. wiki

This only furthers your case that stuff will hit the Earth, so please don't hate my contradiction.
 

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Posted by Tatiana (Member # 6776) on :
 
lol, it's okay! I just meant it's not a gas giant like Jupiter, which we've already seen get hammered in 1994.
 

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Posted by Tatiana (Member # 6776) on :
 
I've been thinking.... what if it was earth? What would we do?
 

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Posted by TomDavidson (Member # 124) on :
 
Stop worrying about my credit card payments.
 

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Posted by The Reader (Member # 3636) on :
 
We would get out of the way, if possible. It would be too close at this point to do anything but watch. The danger is that it could destroy a city or a small nation if it were to impact land in a populated area. If it hits in Siberia or the ocean, I don't think there would be much to worry about, except for a tsunami.

The Tunguska event was caused by something about the size of the Mars impactor. I went to Impact Effects to see what the damage would be in water. I don't know how accurate the site is, but if true the impactor would open a crater in the water about a mile wide. There would be some big waves from that.

I am hoping that the morning of January 30 is clear here. Mars just left opposition, so the viewing should be great for the Americas.
 

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Posted by Launchywiggin (Member # 9116) on :
 
I think they're over-reacting about the devastation of an asteroid. Besides, we've got Chuck Norris.
 

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Posted by Tatiana (Member # 6776) on :
 
Has anyone heard what the latest odds are for the Mars impact?
 

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Posted by pooka (Member # 5003) on :
 
http://www.hatrack.com/cgi-bin/ubbmain/ultimatebb.cgi?ubb=get_topic;f=2;t=051446;p=0&r=nfx
 

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Posted by aspectre (Member # 2222) on :
 
Dropped a third from 3.6% to 2.5% : from 1 chance in 28 to 1 chance in 40
 

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Posted by BannaOj (Member # 3206) on :
 
This says it has been ruled out.
http://www.jpl.nasa.gov/news/news.cfm?release=2007-152
 

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Posted by Noemon (Member # 1115) on :
 

 

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Posted by aspectre (Member # 2222) on :
 
Why the frown? The gravitational slingshot by Mars could deflect it closer to an intersection with Earth.

[ January 14, 2008, 06:32 PM: Message edited by: aspectre ]
 

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Posted by C3PO the Dragon Slayer (Member # 10416) on :
 
I don't know whether to laugh or scream.
 

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Posted by The Reader (Member # 3636) on :
 

quote:

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Originally posted by aspectre:
Why the frown? The gravitational slingshot by Mars could deflect it closer to an intersection with Earth.

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I guess it's time for new sunglasses and binoculars.
 

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Posted by Noemon (Member # 1115) on :
 
Canada to Launch First Space Mission to Hunt Asteroids
 

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Posted by pooka (Member # 5003) on :
 
That's one retro looking satellite, but more of a furniture retro than an space retro.
 

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Posted by Tatiana (Member # 6776) on :
 
Bump for the 100th anniversary of Tunguska.
 

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Posted by Ron Lambert (Member # 2872) on :
 
This should be kept in mind by those who would seek comfort in regarding the Tunguska event as something rare:

quote:

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The late Eugene Shoemaker of the U.S. Geological Survey came up with an estimate of the rate of Earth impacts, and suggested that an event about the size of the nuclear weapon that destroyed Hiroshima occurs about once a year. Such events would seem to be spectacularly obvious, but they generally go unnoticed for a number of reasons: the majority of the Earth's surface is covered by water; a good portion of the land surface is uninhabited; and the explosions generally occur at relatively high altitude, resulting in a huge flash and thunderclap but no real damage.

Some have been observed. Noteworthy examples include the Sikhote-Alin Meteorite fall in Primorye, far eastern Russia, in 1947, and the Revelstoke fireball of 1965, which occurred over the snows of British Columbia, Canada. Another fireball blew up over the Australian town of Dubbo in April 1993, shaking things up but causing no harm.

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quote:

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[An astronomer] speculates that the impact must have punched through to a layer of water frozen as amorphous (not crystalline) ice. This form of ice is what theorists expect to find in comets that came together at temperatures below –190°F (–125° Celsius). [Another astronomer] explains that amorphous ice would rapidly convert to its crystalline form once exposed to space and liberate lots of heat.

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That's an interesting theory. I wonder how much heat would be liberated.
 

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Posted by T:man (Member # 11614) on :
 
What about Apophis, will it come back to hit us?
 

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Posted by Shigosei (Member # 3831) on :
 
Fascinating, Tatiana! Thanks for the update. Deep Impact was such a cool mission

T:man, I think that the consensus is that there is a very slight chance that the 2029 pass could alter the asteroid's trajectory so that it hits in 2036, but the current impact probability for that is 1 in 45,000. More observations over the next few years might let us rule out the possibility of a 2036 impact.
 

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Posted by aspectre (Member # 2222) on :
 
Nope, phase transitions between low-density amorphous ice Ic, glassy water, and (Earth-normal) crystalline ice Ih are extremely smooth compared to other substances. ie There is little latent energy to be stored or released during phase changes.

As a guess, it's more likely the comet had a core of glassy*water held within a shell of ice Ih. And rather than ice being partially gassified and partially melted by the energy of impact with the melt water explosively decompressed (boiled off) as a result of exposure to the vacuum of space, most of the blow-off was the result of glassy water being squirted through the hole punched through the Ic shell by the impactor.

* ie The comet originated as amorphous ice. Then as the comet became warmed by the stronger sunlight during its inward plunge, the amorpheous surface ice transformed into a shell of regular ice. And (a significant portion of) the core Ic became sufficiently warm to transition into glassy water.

[ October 14, 2008, 09:21 AM: Message edited by: aspectre ]
 

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Posted by Noemon (Member # 1115) on :
 

quote:

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Originally posted by Shigosei:
Fascinating, Tatiana! Thanks for the update. Deep Impact was such a cool mission

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quote:

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Originally posted by aspectre:
Asteroid impact sends 20metre/66foot wall of seawater through NewYorkCity metropolitan area.

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quote:

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Originally posted by Ron Lambert:
If 100 times as much matter exploded outward than had been anticipated, perhaps a nuke could be able to blow apart an earthbound asteroid, enough so most of the pieces are small enough to burn up in the atmosphere. Or maybe a well-placed nuke could alter the course of the asteroid sufficiently to miss earth, aided by the rocket propulsion from the enhanced amount of ejected matter.

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quote:

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quote:

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Asteroid impact sends 20metre/66foot wall of seawater through NewYorkCity metropolitan area.

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Wow, aspectre! For a few minutes there my heart stopped.

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quote:

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If you want something else to worry about, the supervolcano under Yellowstone Park, if it blew, would have a caldera 40 miles wide (that is how large the underground chamber of molten magma is right now), and be hundreds of times more powerful than Mt. St. Helens when it blew. Say good-bye to Yogi. Scientists say past eruptions covered the ground deeply for nearly a thousand miles all around with volcanic dust. They also say the supervolcanoe is long overdue for another eruption. There was a special on the Discovery Channel a few months ago (it aired back in April of 2008), a fictional dramatization of this.

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quote:

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Yellowstone Volcano Observatory (YVO) has developed a monitoring plan for the period 2006-2015 to increase our ability to provide timely information during seismic, volcanic, and hydrothermal crises and to anticipate hazardous events before they occur.

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quote:

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Possible future violent events in the active hydrothermal, magmatic, and tectonic system of Yellowstone National Park pose potential hazards to park visitors and infrastructure. Most of the national park and vicinity are sparsely populated, but significant numbers of people as well as park resources could nevertheless be at risk from these hazards. Depending on the nature and magnitude of a particular hazardous event and the particular time and season when it might occur, 70,000 to more than 100,000 persons could be affected; the most violent events could affect a broader region or even continent-wide areas.

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quote:

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In 2003, changes at the Norris Geyser Basin resulted in the temporary closure of some trails in the basin. New fumaroles were observed, and several geysers showed enhanced activity and increasing water temperatures. Several geysers became so hot that they were transformed into purely steaming features; the water had become superheated and they could no longer erupt normally.

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quote:

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Asteroid impacts are easily preventable...

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Might I ask... how do you suggest we prevent them?
 

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Posted by Ron Lambert (Member # 2872) on :
 
Nighthawk, we need two things to prevent major asteroid impacts:

(1) The means for early detection.

(2) The ability to intercept them with sufficient firepower to give them a nudge great enough to alter their course so they miss earth. If intercepted early enough, only a slight nudge would be needed.

They would still need to be monitored after that for undesireable changes of course after they go around the sun. The ideal solution would be to put them into a stable orbit around the earth, so we could go up and mine their useful materials (such as Titanium, Iridium, etc.). Or to be safest we could redirect them to collide with the sun.
 

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Posted by Nighthawk (Member # 4176) on :
 
Well that's hardly "easy", you know...
 

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Posted by Tatiana (Member # 6776) on :
 
But it's quite doable within a reasonable budget and time frame. Say we start with the amount we spend on air traffic safety. The reason I want to start now is that we have no guarantee how long we have before the next impact, nor how severe it will be. Why wait until after it's too late? We did that with Katrina and New Orleans. If we're going to survive we have to start preparing for these clear and imminent threats before they happen.
 

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Posted by Ron Lambert (Member # 2872) on :
 
What could we have done about Katrina and the inundation of New Orleans? We could have had sense enough not to build a city on the seacoast that is below sea level. We could at least have had the sense not to rebuild the city there after it is mostly washed away. But even so, how do we stop a hurricane?

Perhaps it would help if we sent a fleet of tankers containing liquified CO2 into the path of the hurricane, so they could lay down a blanket of super cold CO2, which would hopefully stop any more heat from the warm ocean waters from rising ino the air to fuel the hurricane. Would that work--or make matters worse?
 

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Posted by Orincoro (Member # 8854) on :
 
New Orleans was built *before* it was under sea level. Over a period of three centuries, the outlet of the Mississippi river deposits silt and sediment along its course until the level of the banks causes the entire river to wash over the land. This was known for many many years preceding Katrina, and many people predicted a similar scenario and said it was inevitable. The thing was, New Orleans should have been uninhabitable decades ago.

As for your post about Yellowstone. If that volcano erupts in a fashion similar to (pre)historical eruptions, it will be the end of human life, or at the very outside, the end of all economic and industrial activity on Earth, following the death of 99.9% of humanity.

But the term "overdue," is needlessly alarmist. There is no schedule for eruptions, and there is very concrete evidence showing that the periods between eruptions fluctuates widely. There can be an eruption there ever 100,000 years, but half a million years or more can pass without an eruption. It could go off tomorrow, or it might sit and gurgle for a million years. There is no way to know.
 

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Posted by Traceria (Member # 11820) on :
 
Yellowstone supervolcano, asteriod... On a lighter note, did you all miss that top ten end-of-the-world program that aired this past year? (Yeah, it was so significant that I can't remember the actual name or the station on which it aired.) Global warming has the #1 spot.


 

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Posted by Tatiana (Member # 6776) on :
 
We could have spent $14B to build up the levees, redirect the outflow of the river indirectly rebuilding the barrier islands and so on. Then the hurricane wouldn't have flooded the city. There was an article in 1992 in Scientific American saying the next big hurricane that hits New Orleans is going to flood it, and here's what we need to do to prevent that.

Instead we spent at least $30B in the aftermath, and aren't ready yet for the next one, nor did we prevent all the human suffering that could have been prevented. So, yeah, we were dumb on that one. Let's do better with the asteroid thing.
 

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Posted by Nighthawk (Member # 4176) on :
 
We can build a $14B levee that will stop an asteroid? Cool!

Actually, I'm stunned that, in light of the fact that not much was done to prevent the same thing in the future, people are back to living in New Orleans. I figured it'd be a ghost town by now.
 

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Posted by aspectre (Member # 2222) on :
 
Recent swarm of Yellowstone earthquakes.
 

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Posted by Tatiana (Member # 6776) on :
 
That's pretty scary, considering.
 

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Posted by aspectre (Member # 2222) on :
 
PRESS RELEASE FROM YellowstoneVolcanoObservatory PARTNER UNIVERSITY OF UTAH SEISMOGRAPH STATIONS
"The largest of the earthquakes was a magnitude 3.9 (revised from magnitude 3.8) at 10:15 pm MST on Dec. 27. The sequence has included nine events of magnitude 3 to 3.9 and approximately 24 of magnitude 2 to 3 at the time of this release.
A total of more than 250 events large enough to be located have occurred in this swarm.....Earthquakes are a common occurrence in the Yellowstone National Park area, averaging 1,000 to 2,000 earthquakes a year."
 

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Posted by Ron Lambert (Member # 2872) on :
 
It doesn't sound like the earth is settling down much.
 

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Posted by aspectre (Member # 2222) on :
 
Missed it by that* much.....Would you believe...
"...an asteroid or small comet similar in size to 2009 DD45 exploded over Tunguska, a remote region of Siberia, with the force of up to 15 million tons of TNT, flattening trees for more than 1,000 square miles around."

[ March 02, 2009, 11:21 PM: Message edited by: aspectre ]
 

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Posted by Ron Lambert (Member # 2872) on :
 
A 40,000 mile miss! I hadn't been aware it came that close! Most of them that we hear about pass beyond the orbit of the moon, some 250,000 miles out. I think we dodged a bullet, just barely that time.
 

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Posted by King of Men (Member # 6684) on :
 

quote:

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Originally posted by Tatiana:
We could have spent $14B to build up the levees, redirect the outflow of the river indirectly rebuilding the barrier islands and so on. Then the hurricane wouldn't have flooded the city. There was an article in 1992 in Scientific American saying the next big hurricane that hits New Orleans is going to flood it, and here's what we need to do to prevent that.

Instead we spent at least $30B in the aftermath, and aren't ready yet for the next one, nor did we prevent all the human suffering that could have been prevented. So, yeah, we were dumb on that one.

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Are you sure? You have to consider the probabilities here. What was the probability of Katrina hitting New Orleans in the way that it did? More generally, what is the probability of such a storm in a given year? Suppose it is 1%, to make up a number. Then if you spend 14 billion, over 100 years there is roughly a one-third chance you wasted that money. (100 years is actually rather longer than it's worth considering these things; how much infrastructure from 1908 is still around?) So there is a one-third chance you wasted 14 billion, and a two-thirds chance you saved (30 billion minus 14 billion = 16 billion), for a net expected value of 5.2 billion. On the other hand if you had invested that 14 billion somewhere else, at a very moderate 1% real interest, then at the end of 100 years you would have 37 billion. So with these numbers, building levees is a pretty bad investment. And notice I chose a long time period and a very low rate of return on the other investment.
 

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Posted by Tatiana (Member # 6776) on :
 
The probability of a big hurricane hitting New Orleans eventually is pretty close to 100%. If you live on the Gulf, it happens to you eventually. It's not a whether but rather a when.
 

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Posted by Alcon (Member # 6645) on :
 
Apophis will come with in 22,000 miles in 2029... and may hit us 7 years later in 2036. This is a 237 meter wide asteroid, big enough to wipe out France! Yikes! I didn't realize we knew of any that big that are likely to hit us.

As for the one that just missed us by 40,000 miles -- we only noticed it 8 days before it swept by. And that was one as big as the Tunguska event. Eight days warning! We've gotta get better at asteroid spotting or we're going to regret it.
 

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Posted by Juxtapose (Member # 8837) on :
 
Don't worry, Apophis will miss the keyhole.
 

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Posted by King of Men (Member # 6684) on :
 

quote:

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Originally posted by Tatiana:
The probability of a big hurricane hitting New Orleans eventually is pretty close to 100%. If you live on the Gulf, it happens to you eventually. It's not a whether but rather a when.

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quote:

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When significant numbers of lives are at risk, you spend the extra money to prevent that rather than investing is to make a profit on cleaning up the damage.

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quote:

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Also, when have you known the US gov't to make a decision like what you're suggesting?

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quote:

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Don't worry, Apophis will miss the keyhole. [Smile]

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quote:

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Originally posted by aspectre:
It would have been less expensive to give each&every displaced NewOrleanean a new home from existing housing stock already on sale before Katrina hit than to rebuild the flood walls.

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Ah, but think how much cheaper still it would be now, at 2008 prices!
 

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Posted by aspectre (Member # 2222) on :
 
"A 40,000 mile miss! I hadn't been aware it came that close! ...I think we dodged a bullet, just barely that time."

It came within 0.00047AstronomicalUnits or 70,311kilometres of Earth's center, or ~63,940km/~39,730miles of surface impact. Using Earth's orbital speed of 107,218 km/hour, 2009 DD45 missed by ~35minutes47seconds.

On the other hand, "1,000 square miles" is contained within a radius of only 18miles.

[ March 04, 2009, 07:19 PM: Message edited by: aspectre ]
 

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Posted by King of Men (Member # 6684) on :
 
The impact cross-section is a bit larger than the geometric cross-section, due to gravity and whatnot, so you can likely shave some seconds off that estimate.
 

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Posted by aspectre (Member # 2222) on :
 
Yeah, but I'm cheating already by assuming that the asteroid passed through the tubular-ring cross-section formed by Earth's travel along Earth's orbit, even though the plane of 2009 DD45's orbit is inclined relative to the plane of Earth's orbit.

The slides on the bottom and right of the screen change the orientation of your viewpoint.
The |< and >| buttons change the time-viewed backwards and forwards respectively.
You can also change the view in a manner such that Earth is at the center of the screen, then zoom in using the labeled slide.

[ March 06, 2009, 01:07 AM: Message edited by: aspectre ]
 

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Posted by Tatiana (Member # 6776) on :
 
Here's a follow up on that Winnebago-sized chunk that hit North Africa a few months ago. It seems that they were able to find meteorites that made it all the way to the ground, and they're very unusual. The findings are Nature's cover story this month.
 

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Posted by ana kata (Member # 5666) on :
 
Oh, something just occurred to me relative to an argument some people way back in the first few pages brought up. They said no big impact has ever happened in recorded history. Setting aside the fact that recorded history is very short, and significant impacts have definitely occurred during that time, e.g. Tunguska, I had an idea that sort of negates their argument.

If a really big impact DOES occur, one of the certain-extinction size that I'm most worried about, then there won't be any way for it to be part of anyone's recorded history because recorded history will end at that point.

Perhaps in a few hundred million years someone else, some non-human species, could be around once again to record their own history. But perhaps not. We really don't know anything about the likelihood of species-who-write evolving on planets like the earth. So far we only know of just the one.
 

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Posted by ana kata (Member # 5666) on :
 
I've just been reading about Zion's camp, an episode in the history of The Church of Jesus Christ of Latter-day Saints, otherwise known as the Mormons. The church at that time was concentrated mostly in Kirtland, OH and Independence, MO. When the Saints in Independence were being harrassed, mobbed, murdered, raped, etc. and their homes and stores and properties were being destroyed by the locals trying to run the Mormons out, Joseph Smith, Jr. and a few hundred men from the Kirtland area rode to the rescue in a semi-military group known as Zion's Camp.

The expedition suffered through great hardships and difficulties to reach Missouri, at which time the government forces they'd counted on to back them up never materialized, and God, speaking through revelations to Joseph, withheld his permission for them to attack the local mobbers. Apparently self-defense was allowed but not all-out war, and the Saints were urged to proclaim peace. In the meantime, Zion's camp came down with cholera, and most were very sick, and many died. The Camp was forced to disband and make their way home piecemeal as best they could, their numbers sorely depleted. It seemed a terrible defeat.

At the time it was tempting to believe God had abandoned the Saints altogether. The cholera was understood by some at the time to be a scourge sent from God to punish them for internal contention in the camp. Now, of course, we would attribute it to the poor standards of water hygeine. They probably didn't keep their latrines in an area that was downstream from their drinking water supply. Something simple like that might have prevented the disaster. As it was, the Saints ended up losing almost everything in Missouri and having to leave. What does that say about how we should understand the way God succors his people?

That thought was 'impacting' in my head this morning with the question of whether God would reach out and save us from an asteroid impact from which we had means but not sufficient motivation to save ourselves. I'm thinking that God didn't save his Saints from cholera when they didn't even realize yet what caused cholera, and how to save themselves from it. I don't think he's going to save us from an asteroid impact that we can clearly see coming, but are too apathetic to do anything about. I think it's up to us.
 

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Posted by ana kata (Member # 5666) on :
 
I'm also thinking about the phenomenon of Cassandra. When I make these warnings, I feel like a Cassandra, someone who warns of disaster but nobody listens. It's interesting to realize that the original Cassandra of legend was right. She was Hector's sister in Troy, and predicted that disaster would come to their city, which of course it did in the Trojan War.

I see society as analogous to the body of a human or other animal. Each individual in a civilization is like a cell or other part of the body of society. Some of us are like feet, others like skin or hands, others are brains or bones.

The Cassandras of society are sort of like our eyes, because they see disasters that are headed our way, and they see how we can take steps to avoid them. But they are eyes without any nerve connections to the brain. They can see what's about to happen, but they don't have any way to hook in to the motor nerves and get them to step in another direction to avoid the danger.

What Cassandra needs is to develop some axons into the higher executive control functions of the body of civilization. That is what is lacking. I wonder how to go about doing that?
 

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Posted by Noemon (Member # 1115) on :
 
The British were taking the threat a bit more seriously than anybody else, the last time I checked. That was a couple of years ago, though. I wonder what kind of progress they've been making in their plans in the intervening years?

Ana kata, what made you decide to switch from your Tatiana handle to this one?
 

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Posted by ana kata (Member # 5666) on :
 
Ah, I forgot. In order to change the tagline on the topic header I have to change back to ana kata, or it won't let me edit that post. Then I forgot to change back until you mentioned it.
 

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Posted by Tatiana (Member # 6776) on :
 
There. Back now.
 

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Posted by aspectre (Member # 2222) on :
 
http://www.newscientist.com/article/dn17073-nearby-asteroid-found-orbiting-sun-backwards.html

How do you miss a 2to3kilometres-wide asteroid with a 3.4year orbit that came within 0.084AU* of Earth on 9Jan1999?

* According to Nasa's Horizon ephimerides calculator.
It came within 0.0811AU according to the Orbital Simulator (link in my previous post above).
 

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Posted by Tatiana (Member # 6776) on :
 
Wow, that's a big one. Maybe with more viewings we'll find a somewhat different orbit farther away, or maybe not. I think we're still missing a lot of the earthgrazing objects.

How many miles is .084AU? 93,000,000 * .084 = about 900,000 miles. So would that be about 4 times as far as the moon? That's pretty darn close.
 

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Posted by aspectre (Member # 2222) on :
 
~12,600,000kilometres/~7,800,000miles, or almost 33 times the average distance to the Moon. Due to the asteroid's orbital inclination, the closest it flys under Earth's orbit is ~3,500,000kilometres/~0.046AU/~2,170,000miles.

[ May 09, 2009, 08:17 PM: Message edited by: aspectre ]
 

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Posted by aspectre (Member # 2222) on :
 
Dude gets hit by meteor while walking to school.

The writing mostly reminds me that science reporters were amongst the first fired during the downturn in newspaper subscriptions.
 

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Posted by The Reader (Member # 3636) on :
 
How could that meteorite have been going that fast? Air resistance almost certainly should have slowed it to around 200-300 mph.
 

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Posted by aspectre (Member # 2222) on :
 
Amongst other things that would have triggered a science reporter's skepticism.
 

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Posted by Samprimary (Member # 8561) on :
 
Yeah, Schoolboy survives direct hit by meteorite travelling at 30,000mph, does not survive flash vaporization
 

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Posted by aspectre (Member # 2222) on :
 
http://uonews.uoregon.edu/archive/news-release/2009/7/californias-channel-islands-hold-evidence-clovis-age-comets

http://en.wikipedia.org/wiki/Younger_Dryas_impact_event

[ July 25, 2009, 07:09 AM: Message edited by: aspectre ]
 

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Posted by Tatiana (Member # 6776) on :
 
Interesting articles. How would we cope now with something like this, I wonder? If most of North America burned and there were huge tsunamis on one coast? It would be a struggle to keep civilization going, I think. These things happen pretty frequently in our solar system. Witness the recent Jupiter impact, as well.

We need an asteroid defense, guys. Like, soon. This is entirely preventable. We have the technology to protect ourselves. If we don't use it, whose fault will it be if we get hit? I don't see how we can blame anyone but ourselves in that case.
 

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Posted by Tatiana (Member # 6776) on :
 
http://media.skyandtelescope.com/images/Hubble-Jupiter-Scar_7-23-20.jpg

Here's a great hubble picture of the latest impact site on Jupiter.

Note: that black spot where the impact was is approximately the size of the Earth.

[ July 27, 2009, 01:52 AM: Message edited by: Tatiana ]
 

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Posted by The Rabbit (Member # 671) on :
 
http://xkcd.com/618/
 

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Posted by Tatiana (Member # 6776) on :
 
I hope Jeni didn't see that.
 

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Posted by Tatiana (Member # 6776) on :
 
Impact on North America 13,000 years ago kills off megafauna, including mastodons, woolly mammoths, big sloths, etc. according to a new theory.

http://www.skyandtelescope.com/news/home/54830807.html

Synopsis is there. For the full article you have to get the magazine. The magazine is really interesting and a great source of astronomical information, in case anyone wants to get it.
 

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Posted by Noemon (Member # 1115) on :
 
Love the thread title change, Tatiana!
 

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Posted by Tatiana (Member # 6776) on :
 
Thanks. =)

Btw, there's also a podcast linked from the article that should be free.
 

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Posted by King of Men (Member # 6684) on :
 
The thread title is indeed funny. I must say I preferred the old theory, though, that humans wiped them out.
 

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Posted by The Reader (Member # 3636) on :
 
Don't be down, KoM. I'm sure we still helped.
 

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Posted by King of Men (Member # 6684) on :
 
Yes, yes, but "Helping a giant meteor impact" just doesn't have the same visceral satisfaction as "Wiping out megafauna with nothing but stone spears". It doesn't feel the same when the species in question has had a bloody great rock heaved at it and you're just kicking it when it's down.
 

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Posted by aspectre (Member # 2222) on :
 
50kiloton blast over Sulawesi, Indonesia
 

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Posted by Tatiana (Member # 6776) on :
 
I want to point out that a huge hazard to the world that I first discussed and urged action on 10 years ago is finally becoming a topic to which the government is paying attention. Next year the U.S. Government will publish a plan to deal with asteroid impacts.

So, finally this is being taken seriously, thank goodness. I just want to point out that I recognized this hazard and began pointing it out over 10 years ago.

I had to do this as an engineer several times, too, before I got my coworkers to begin listening to my ideas. As a female with a soft voice, I was often overlooked on the jobsite until I pointed out to my coworkers that I understood what was going on in several situations well before they did, and tried to tell them what I knew, and they didn't listen. Of course by the time the problem was resolved they had all forgotten what I said originally, hence the need to remind them. After this happened 3 or 6 or 10 times, they began to listen up front as well.

So this is not to say nyah nyah I told you so, though of course my heart isn't entirely free of any hints of that sort of feeling. =) This is just to document the situation so that we may recognize solutions to future problems more quickly.
 

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Posted by aspectre (Member # 2222) on :
 
"Over the past 3 years, a loosely confederated group of researchers has argued that an asteroid or comet struck North America about 13,000 years ago, wiping out the woolly mammoth, the giant sloth, and other large animals.
Experts say they have shot down most of the supposed evidence, but one finding remained: nano-scale diamond crystals that could have formed only under the extreme pressure of an impact. Now, a group of experts has dismissed this evidence as well, putting what many see as the final nail in the coffin of the mammoth-killer impact."
 

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Posted by The White Whale (Member # 6594) on :
 
I just attended a seminar discussing extreme volcanic explosions as the likely cause of the major extinction events in the Earth's history. There is more evidence for correlation (and this guy says causation) of extinction events and flood basalt formation than of extinctions and impacts.

He went through all of the evidence of high-pressure build up of carbon dioxide under certain crustal features, which then explode and create many of the features previously associated with impact events. Also, many of the "ground zeros" are near flood basalt, but the flood basalt layers extend far below the impact layer. Simply put: the impacts cannot be the cause of the flood basalts, and they are too often found together to be simple coincidence. Instead, it seems more likely that the flood basalt is a symptom of extreme high pressure which theoretically leads to huge explosions, leaking carbon dioxide, sulfur, and other toxic gases into the atmosphere.

Here's a link describing a little of what he gave in today's seminar.
 

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Posted by Tatiana (Member # 6776) on :
 
This issue of Sky and Telescope will hit the newsstands soon. I just wanted to point out the story to those who have an interest in this subject, and incidentally keep this thread alive. =)
 

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Posted by Jake (Member # 206) on :
 
NEOShield to assess Earth defence
 

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Posted by ZachC (Member # 12709) on :
 
All of the people on this thread taking this topic seriously are morons. On the off chance, that an asteroid large enough to do serious damage to the Earth came near in its orbit, at least one of the advanced nations on this planet would detect it in time. Our resources are better spent fighting actual threats like global warming and overpopulation than random juvenile delusions straight out of a bad Sci-Fi novel.
 

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Posted by Dan_Frank (Member # 8488) on :
 
Insightful.

No, wait. That other thing.
 

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Posted by T_Smith (Member # 3734) on :
 

quote:

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Originally posted by ZachC:
All of the people on this thread taking this topic seriously are morons. On the off chance, that an asteroid large enough to do serious damage to the Earth came near in its orbit, at least one of the advanced nations on this planet would detect it in time. Our resources are better spent fighting actual threats like global warming and overpopulation than random juvenile delusions straight out of a bad Sci-Fi novel.

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