Random Thought Table: A good argument for terraforming

[jeriendhal]

Okay, follow along with me.

The Problem: Mars is a crappy planet to try and land on. The atmosphere is too thin to aerobrake during re-entry, you need huge parachute, but there's just enough air to burn anything coming down to crisp if they don't have a heat shield. At one ton the Curiosity rover is the biggest thing we've been able to land. Anything with humans on board must be a lot bigger. Maybe too big for chutes and retro-rockets.

The Solution: Obviously a thicker atmosphere would help with the chutes and braking, and make the weight of that heat shield worthwhile. So obviously we should start dropping comets on it to thicken the atmosphere first, then land humans.

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What?

Comments

[seawasp]

Heh. If you have the resources and energy to drag around comets large enough to provide an atmosphere for Mars, landing people on Mars has long since become a trivial exercise.

[harvey-rrit.livejournal.com]

Except for the getting-them-to-agree-to-it part.

[seawasp]

No, getting people to agree to go to Mars is easy.

[harvey-rrit.livejournal.com]

Getting people to go to a planet isn't worth living on except on a lark is easy. A civilization whose people can afford to do that is a civilization that has already started moving asteroids around.

[zarpaulus.livejournal.com]

There were 200,000 applicants for MarsOne. And that's with a four-person pod that would take most of a year to arrive and no terraforming.

[solarbird]

You're forgetting that we need a control Mars for this experiment, too.

[jeriendhal.livejournal.com]

Sure. First, hit Venus with a couple of Dinosaur Killers to blow off the atmosphere...

[harvey-rrit.livejournal.com]

Oh HALE no.

You need to:

a ) use a Moonformer-grade collision with something the size of, say, Mercury*;

b ) put that much carbon dioxide back**, but only a quarter as much nitrogen***, along with about as much water as makes up, say, Callisto, plus enough helium to soak up UV and keep the water vapor from being broken down like it did in the original case;

c ) leave a big piece of tinsel between Venus and the Sun for the five thousand years it's going to take for the CO2 to be absorbed, until which time the planet is not going to cool below about 600 Kelvin;

d ) spend the whole 5000 years herding debris from the collision into a halfway decent moon and keeping it just outside the Roche limit, so you can get a decent day-night cycle going with tidal action; and

e ) constantly remind yourself that if you went looking for planets around another star you'd still have to do all this crap, but from aboard a generation ship instead of in a system that has Hawaii. Even if you do only go on vacation every other decade. (Though it is for the whole decade.)

(*Mercury itself has the virtue of not needing to be moved anywhere near Earth's orbit.)

(**If it isn't locked up in carbonates the least of your troubles will be a planetary crust made of cement.)

(***Otherwise everybody goes into narcosis and dies.)

[solarbird]

Oh mo. Right now oxygen is a lifting gas and the upper atmosphere is breathable. I WANT MY CLOUD CITIES OF VENUS.

[jeriendhal.livejournal.com]

Thanks for reminding me. I need to bug James to get those 1979 Analogs he borrowed from me back.

[solarbird]

I think you misspelled "1939 Astoundings."

[jeriendhal.livejournal.com]

Nope, got it right. I loaned three issues to him that featured a floating city large aerostat flying in Venus' upper atmosphere as part of a terraforming project.