[Space] Terraformed Venus as a setting

[malloyd]

Originally Posted by Mailanka

Yeah, but that's on a geological scale, right? Over the course of 10,000 years, it wouldn't really substantially change your atmosphere, right?

Or slower. For example *Venus* lacks a significant magnetic field, and has about 100 times as much atmosphere as Earth. It's sometimes credited with the low amount of water seen in the Venusian atmosphere, not because any significant amount of water can be carried away, but because it may have carried off a substantial number of hydrogen atoms from the outermost layer, though there are alternatives.

In any case, the mechanism is pretty simple. Lacking a magnetic field means the solar wind is absorbed in your upper atmosphere. This raises its temperature, and hence average velocity of its atoms, and the rate of Jeans escape is pretty sensitive to temperature.

[tantric]

As a thought experiment, let's assume that it is possible to create an algae that can live in the cloud layer. I think THS science could do that with ease. So, what happens a million years later? Does the Gaian principle lead to more life, or does the algae use up some critical resource and die out? I've always wondered if this happened to Mars - that Mars is harsh *because* it supported life. What if the first life forms got their energy from binding O2, present from outgassing or whatnot, to iron?

[Nereidalbel]

Originally Posted by tantric

As a thought experiment, let's assume that it is possible to create an algae that can live in the cloud layer. I think THS science could do that with ease. So, what happens a million years later? Does the Gaian principle lead to more life, or does the algae use up some critical resource and die out? I've always wondered if this happened to Mars - that Mars is harsh *because* it supported life. What if the first life forms got their energy from binding O2, present from outgassing or whatnot, to iron?

Either life adapts to the changing atmosphere, or it dies. Had life not figured out how to use oxygen when the first photosynthetic organisms appeared on Earth, there would be no humans. After all, way back then, oxygen itself was poison!

[Vaevictis Asmadi]

Yet some of the anaerobic organisms did survive in isolated places. They would still be around today... though the vast majority of Earth would be barren and lifeless.


Regarding Venus and Mars, another factor that cannot be ruled out is volcanism. Venus has been volcanically active for a while, possibly quite recently. Mars, on the other hand, has been geologically dead for a long time, so it isn't generating any significant new gas.

Captain Joy: I suggest searching: mars magnetic anomolies. There are a few papers Google found under that.

[acrosome]

Originally Posted by Mailanka

Listening to people discuss solar shades for Venus instantly brought to mind the image of a "black sun", an eclipsed sun with its ring of fire staring balefully down at the alien landscape of this terraformed world.

"Black Sun" certainly is an interesting bit of phraseology. Google reveals that among other things it can refer to an occult symbol related to Germanic neopaganism, a major part of Mesoamerican cosmology, and there is some sort of alchemical angle as well. Here's an even more cool picture:

http://commons.wikimedia.org/wiki/Fi...of_fire%22.jpg

There are many more if you google "annular eclipse."

I've been reading more about Terraforming Venus, and there are certainly non-superscience ideas for speeding up rotation and even tilting the axis- though they are nonetheless epically epic endeavors and take at least 30 years- but none for moving its orbit significantly. Thus all schemes need some sort of sunshade. One interesting thing is that a year could be a nicely regular eight months of 28 days, with a system for leap years.

I've also found schemes that would actually leave deposits of magnesium and calcium carbonate all over the place, which is handy for cement and numerous other uses. Score!

Leaving Venus in it's own orbit gets a year that is 0.615 Earth years, though. That's annoying for someone who would be trying to stat cities and the surrounding countrysides, as far as cropland productivity, anyway. I've still been thinking about it, though. Anyone have simple ideas for dealing with it?

[lwcamp]

Originally Posted by acrosome

Leaving Venus in it's own orbit gets a year that is 0.615 Earth years, though. That's annoying for someone who would be trying to stat cities and the surrounding countrysides, as far as cropland productivity, anyway. I've still been thinking about it, though. Anyone have simple ideas for dealing with it?

No axial tilt. Without seasons, you can grow crops without regard to the length of the year.

Luke

[Flyndaran]

Originally Posted by lwcamp

No axial tilt. Without seasons, you can grow crops without regard to the length of the year.

Luke

That would also mean that the poles stay really cold and dark.

[acrosome]

Originally Posted by Flyndaran

That would also mean that the poles stay really cold and dark.

And it's boring. And complicates working out climate. What effect do such stable wind patterns have? How far from the equator do the tropical jungles spread?

[Vaevictis Asmadi]

Dark, yes, but with a thick atmosphere they won't be nearly as cold as the poles of Mercury.

[Flyndaran]

Originally Posted by Vaevictis Asmadi

Dark, yes, but with a thick atmosphere they won't be nearly as cold as the poles of Mercury.

But being much colder than earth's poles would limit their usefulness quite a bit.