New theory unravels magnetic instability

spaceref.com ^ | 10 Dec 02 | Los Alamos

[DannyTN]

ok, I see your point. That effectively kills the idea of a sunblocking satelite, except for perhaps moving natural satelites of size into place around venus. And then you would have to position it in a perfectly synchronous orbit so that it always was in eclipse mode instead of reflecting more sunlight. And then there would be tidal effects that I bet would offset the loss of light.

I'm not sure what percent of the total sunlight is blocked in a Solar Eclipse, but it ends up being a total solar eclipse on only 1/2 of 1% of the earth's surface. Therefore the moon would block more light if it was closer and since the moon is 2000 miles in diameter and Venus' diameter is 80% that of the earths. It seems like even if you had a moon size object closer to Venus that the moon is to earth, you are still only blocking a portion of sunlight.

[Doctor Stochastic]

But the CO2 would just freeze again quickly. All the nukes that the world has won't melt the ice caps. They could contaminate Mars enough to make it uninhabitable (2 prefixes and a suffix) for a long time.

[Doctor Stochastic]

By Kepler's laws, to be synchronous to Venus, you need to be at the same distance from the Sun as Venus.

[Sentis]

Actually the CO2 will not freeze again quickly in fact the more CO2 and water vapor in the martian atmosphere the warmer the atmosphere will become. That is the point of unfreezeing the CO2 in the first place regardless if you do it quickly with nukes or slowly with a mirror or lense it is the same process. Contamination of the type you suggest is a myth. By the time we are ready to actually settle on the surface of Mars 100-200 years later all radioactivity from the bombs will long be gone. Also the amount of Radioactivity that will linger at the equator (which will be the area we will first be seeding with bacterial, plant, and animal life will be small and will have no deterious effect on the types of life we will be planting there.

[r9etb]

What has an Isp of 2000 sec?

Various types of electric thrusters -- ion, plasma, or arcjet -- can and do achieve that sort of Isp. (Very low thrust, however.)

[SunkenCiv]

A Blast from the Past, from a bit more than three years ago.