[Spaceships] Million Merchant Marathon

[scc]

Originally Posted by Fred Brackin

It's obvious that nitrogen is desirable as an atmospheric dilutant anywhere they don't have it but what does isolating it on Venus and then getting rid of it have to do with the atmosphere of Venus? That's 95% carbon dioxide.

I've seen proposals that capture the carbon and turn it into many many miles tall cooling towers of diamonoid (pumping heat from the lower atmosphere to the upper where it is more easily gotten rid of).

You're probably going to need the nitrogen on Venus to make bio-mass when it cools enough.

By contrast the moons of Neptune are very unlikely to e terraformed and you can mine the solid nitrogen with cryogenic nanites or aomething like that.

Because the nitrogen in Venus' atmosphere alone gives it an atmospheric pressure 3 times that of Earth's, so if I want an Earth normal atmosphere on Venus, a lot of that has to go.

As for cooling Venus, I'm taking the sunshade approach, once it's complete it seems like it'll take 70 years for the CO2 in it's atmosphere to liquefy.

You might be right about the bio-mass bit but.

Originally Posted by Anthony

The simplest option for Mars is to head out to the Kuiper belt or Oort cloud (depending how patient you are; further out = less delta-V but more time) and start kicking comets towards Mars. Mostly what this will get you is water, but you need a thousand times more water than you need nitrogen, so the ammonia content of the comets should do the job.

Scooping up the atmosphere of Venus won't do you any real good, because it's not made up of the things you need anyway; it's mostly carbon dioxide, which isn't what Mars needs. Venus is a ridiculous mega-engineering project, far beyond the scope of Mars, but if you're really dedicated to doing it you want to deliver large amounts of water, re-spin the planet, restart tectonics so you can bury a lot of the CO2, and give the entire planet a sun shade. You might be able to start in on that by whacking it with a substantial planetoid, assuming you don't mind waiting a million years for it to be habitable.

The CO2 is actually useful because the carbon will be needed for creating biomass and the excess water can be combined with hydrogen imported from Saturn to make water. I expect that this plan will involve starting soil conditioning really early.

Originally Posted by Agemegos

Titan is 48% larger than the Moon. On the other hand it is less dense. Taking one thing with another, Titan's escape velocity is 2.64 km/s, whereas the Moon's is only 2.38 km/s. That's a small difference, but Titan is also a lot colder than the Moon. That means that the gas molecules in its atmosphere move more slowly, and therefore that fewer reach escape velocity.

Using the formulas in GURPS Space, Titan's black-body temperature is 90 K and its minimum molecular weight retained works out to 26.9 a.m.u. Whereas the Moon's black-body temperature is 278 and its minimum molecular weight retained works out to 102.5 a.m.u. The molecular weight of nitrogen gas is 28 a.m.u. So that's why Titan has retained nitrogen whereas nitrogen would escape fairly quickly from the Moon.

The Moon lacks an atmosphere more because it formed so late in the development of the Solar System then anything else.