I doubt I'll write a story on Mars, but I'm sure this is of interest to some here. I think there was a thread about this a while back.
Posted by HSO (Member # 2056) on :
I've always enjoyed SF stories that dealt with terraforming Mars. As a writer, the idea that we may eventually be forced to settle there is appealing. Even just settling there for no reason other than we want to do it appeals to me.
Plus, there's the whole less-than-Earth-gravity thing to consider, and any evolutionary changes that occur due to this.
Great stuff.
[This message has been edited by HSO (edited February 03, 2005).]
Posted by SteeleGregory (Member # 2049) on :
Interesting article. They have one sketchy detail though. CO2 isn't a greenhouse gas unless it's cold and abundant enough to form clouds. CO2 makes a thicker atmosphere on Earth, but not a hotter one.
And I wonder if all that octafluoropropane would be hard on our lungs. Or will the eventual rainstorms scrub it from the atmosphere?
Posted by Survivor (Member # 213) on :
Octafluoropropane sounds scary, but it's actually pretty safe in the amounts their considering. CO2 needs to be warm to be a good greenhouse gas. The current problem is that most of it is frozen and thus doesn't have much warming effect. But there are much bigger problems with this scenario which haven't really been addressed at all. This is just one of those "slow news day" stories. Let's do a keyword search through NASA's archives looking for stuff about "global warming" and "radical climate change".
Posted by SteeleGregory (Member # 2049) on :
Okay. I should have said "just the right temperature" to form clouds. CO2 doesn't do much atmospherically as a solid, but it also doesn't seem to have any effect on climate on a planet as warm as Earth. Water vapor is a drastically more effective (and easily observable) greenhouse gas in our atmosphere.
I suppose if you could super-saturate the air with CO2, it would overcome the temperature issue and get thick enough to start trapping heat.
Posted by Rocklover (Member # 2339) on :
Sorry to display my ignorance, but are the Jovian planets hot inside? I know there's heavy, heavy air pressure, but is there warmth? I know Venus has the greenhouse thing going but it's closer to the sun. Mars is much farther and colder. So what I'm wondering is, would the effect of building up the clouds supercede the planet's basic low temperatures? Don't know. I'm asking.
[This message has been edited by Rocklover (edited February 04, 2005).]
Posted by Survivor (Member # 213) on :
It depends on what you mean by "hot" and "inside". The atmospheric temperature does climb pretty noticibly with the density and pressure, if you go deep enough it gets very warm indeed. There's also quite a bit of radiation.
On the other hand, you could be deep enough in any of the Jovians' atmospheres to consider yourself "inside" and still have it be pretty darn cold...er, really darn cold.
But presuming you're excluding Pluto from being considered a Jovian planet and that you mean the same thing by "inside" that most people mean, they're pretty hot inside, yeah.
Posted by Rocklover (Member # 2339) on :
Okay, but wouldn't it take a LOT of atmosphere to create enough warmth to overcome Mars' cold temperatures?
Here's another question. Don't plants need a certain intensity of sunlight to grow? Suppose you did manage to create a cloud cover and warm up Mars's surface, would there be enough sunlight to grow plants?
[This message has been edited by Rocklover (edited February 05, 2005).]
[This message has been edited by Rocklover (edited February 05, 2005).]
Posted by mikemunsil (Member # 2109) on :
Well, there's enough sunlight to run some rovers around. Surely plants are more efficient at extracting energy from sunlight than engineers.
Posted by Rocklover (Member # 2339) on :
Not necessarily. We don't grow plants in a basement...I mean, except for the molds and fungi lurking behind my water heater. That's because there's insufficient light. While there are shade-loving plants like lettuces, there are few which produce food suitable for humans. Look at tundra foliage. There are plants there, but they're not much good for a tossed salad.
What I'm getting at is, the whole idea of terraforming is to make the place livable for humans, right? So you have to be able to grow plants for FOOD. And food- producing plants need a lot of sunlight.
Although the idea of terraforming is intriguing, I am skeptical that edible plants (for humans) could be produced on Mars suffiient to feed a human population.
[This message has been edited by Rocklover (edited February 05, 2005).]
Posted by zerhoe (Member # 2188) on :
Doesn't anyone else find it creepy...jumpstarting life on mars could pose some serious risks couldn't it?
I mean what about all sorts of bacteria that could be harmful? Just doesn't sound natural to me, not that what we're doing here on Earth is any more so.
But back to the point, methinks it would be asking for trouble, and why even fantasize about it when we have enough trouble on this planet as it is...but then again that's like saying why imagine! why write!
Posted by Survivor (Member # 213) on :
Plants on Mars would have to make due with something less than half the amount of sunlight they'd get on Earth. In and of itself, that's easily doable if you have the plants under an insulated dome and use mirrors to concentrate the light.
But getting the entire planet to the point where it had enough insolation, atmosphere, and biomass to support an Earthlike ecology would be a major undertaking. You've hit on an important point with your question about the atmosphere (though the Jovian atmospheres were a tangent, those are warm because of energy produced by the planets themselves rather than because of energy collected from the sun). Mars would need a much thicker atmosphere than Earth has in order to have the same surface pressure/density/mixture. And it would need the same pressure/density/mixture in order to support liquid water at a temperature that would be hospitable to plant life.
We discussed this on the other thread about terraforming Mars. Basically, it works out as much easier to live under domes and wait until you develop some kind of miracle terraforming tech.
Posted by Rocklover (Member # 2339) on :
I've read there is speculation of SOME possibility that at the bottom of the Vallis Marinas, which is supposed to be three or four times the depth of the Grand Canyon, there COULD be a warmer climate and MAYBE some liquid water. Intriguing.
Posted by Survivor (Member # 213) on :
There was also the thing about possible mudflows near some of the volcanoes.
I still think that domes are the best bet for a lower gravity, thinner atmosphere planet like Mars. They're just more economical.