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Sat, 23 Feb 91 01:47:50 -0500 (EST)
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Date: Sat, 23 Feb 91 01:47:44 -0500 (EST)
Subject: SPACE Digest V13 #193
SPACE Digest Volume 13 : Issue 193
Today's Topics:
Re: Terraforming, sun shield
Re: Commercially-funded Space Probes (was Re: Space Profits)
Re: Shapes From Shading? (was: Re: Martian Mystery?)
Re: Terraforming, sun shield
Re: Terraforming, sun shield
Re: Terraforming, sun shield
Re: Shapes From Shading? (was: Re: Martian Mystery?)
Re: Commercially-funded Space Probes (was Re: Space Profits)
Re: Shapes From Shading? (was: Re: Martian Mystery?)
Re: Terraforming, sun shield
Re: Terraforming, sun shield
Re: Terraforming, sun shield
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In article <1991Feb22.184557.18844@bradley.bradley.edu> moonman@buhub.bradley.edu (Craig Levin) writes:
> Could one use close approaches by minor planets or comets to
>somehow plow off the atmosphere? ...
I saw a paper in JBIS proposing impacts by the largest half-dozen asteroids,
to simultaneously blast off a fair bit of the atmosphere and spin up the
planet (its rotation is annoyingly slow). My dim recollection is that the
blast-off scheme does not, in fact, work as well as the authors proposed.
It's really hard to get rid of 90atm of gas around an Earth-sized planet.
--
"Read the OSI protocol specifications? | Henry Spencer @ U of Toronto Zoology
I can't even *lift* them!" | henry@zoo.toronto.edu utzoo!henry
------------------------------
Date: 22 Feb 91 19:24:38 GMT
From: tardis@athena.mit.edu (Ronald G Lovejoy)
Subject: Re: Terraforming, sun shield
In article <1991Feb22.164032.16901@zoo.toronto.edu>, henry@zoo.toronto.edu (Henry Spencer) writes:
|> In article <5705@optilink.UUCP> cramer@optilink.UUCP (Clayton Cramer) writes:
|> >... Try big dirigibles in the upper atmosphere, carrying algae
|> >to do the CO2 -> O2 conversion. Much more practical.
|>
|> Well, not really, if what you want is a habitable planet. If you think
|> 90 atmospheres of CO2 with clouds made of sulfuric acid droplets is a
|> hostile environment, 90 atmospheres of *oxygen* has it beat in spades.
|> High-pressure oxygen is corrosive almost beyond imagining, especially
|> when hot. The real problem with terraforming Venus, far more significant
|> than the shortage of water or the nearness to the Sun, is the need to get
|> rid of most of the atmosphere somehow.
I'm not sure that that's really much of a problem. CO2 is a heavier gas than O2 and since Venus and Earth have about the same mass (and Earth has 1 atmosphere of pressure), a lot of that liberated O2 may escape into space. Additionally, when these microorganisms take in the carbon and some of the sulfur, a lot of it will percipitate out of the atmosphere, thereby reducing the atmospheric mass some more.
One possibility for solving the water problem may lie with the sulfuric acid. Although I haven't had any Chemistry since my freshman year, I understand that acids should have a hydrogen radical. By seperating out the hydrogen and combining it with oxygen, one can supply the water needed for the algae. Also, there should be some hydrogen locked up in the rocks on the surface.
This particular discussion seems to be getting away from the actual focus of this group, so how about a new newsgroup, sci.terraform?