<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>nkoren</author><text>You still have to spin up the planet. An earth-like atomosphere would freeze solid on the dark side, and air from the light side would be rushing into the dark side, where it would freeze, until the light side was stripped of its atmosphere too. So the atmosphere would just be a mobile ice cap on the far side, rotating around the planet once per year, with the only gaseous atmosphere being a small, constantly-moving region of sublimation at the terminator betwen the light and dark sides.&lt;p&gt;Make the atmosphere thick enough to not freeze on the far side, and it&amp;#x27;ll be absolutely boiling on the near side. The slow rotation means that there is no happy medium: either you&amp;#x27;ve got an atmosphere freezing solid, or you&amp;#x27;re cooking half the planet at any given moment.</text><parent_chain><item><author>mabbo</author><text>I love this idea, but there is something missing: nitrogen. You need to extract some of that from Venus as well, and bring it with you.&lt;p&gt;But if you really want to have fun with terraforming you should make Venus earth-like. I suggest an exciting starting point: build a solar shade at the Lagrange point and block the sun. That would eliminate most of the hard problems with Venus temporarily while we did whatever work is needed to get it spruced up. CO2 freezes to dry ice below -80C or so. You could let through just enough sunlight to get the atmosphere at a pressure humans can survive- then all we need is warm clothes and an oxygen tank.&lt;p&gt;Once Venus is in that state, the problem is simpler- how to get all the carbon and oxygen separated so that the carbon stays in some kind of solid form.&lt;p&gt;Oh, and we&amp;#x27;ll want to go get a load of hydrogen, likely from Jupiter, to mix with that Oxygen to form water. Your fleet of transports moving CO2 to Mars needs to make a detour on the way back.&lt;p&gt;Edit: fixed a word and also lol, just start with building a planet-sized solar shade, says some a-hole on the internet.</text></item><item><author>Teever</author><text>I&amp;#x27;ve wondered about the feasibility of transporting the abundant CO2 in the Venus atmosphere to Mars for the purposes of terraforming both planets at the same time.&lt;p&gt;It&amp;#x27;s been a while since I&amp;#x27;ve done the the envelope math but if I recall correctly there is more than sufficient CO2 on Venus to provide an atmosphere for Mars the issue is just transportation.&lt;p&gt;The last time I thought about it I considered some sort of massive floating solar powered comet builder that would cool the atmosphere into large chunks of dry ice that could then be wrapped in a metal sabot so that the comet could be accelerated to mars via a mass driver.&lt;p&gt;As with everything in space and terraforming the key is scale so the equipment used would need to built in situ out of carbon from the Venusian atmosphere.&lt;p&gt;We are of course still a ways away from mastering self replicating carbon based engineering but the idea of terraforming both planets at the same time is neat to me.</text></item></parent_chain></comment><story><title>Mars Problems vs. Venus Problems</title><url>http://interconnected.org/home/2020/09/23/venus</url></story>
<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>CapitalistCartr</author><text>If you can build a planetary solar shade, engineer blue-green algae to survive the harsh conditions, and as soon as the temp on any part of the planet drops to survivable, seed the algae. It&amp;#x27;ll explode, sucking up the carbon.</text><parent_chain><item><author>mabbo</author><text>I love this idea, but there is something missing: nitrogen. You need to extract some of that from Venus as well, and bring it with you.&lt;p&gt;But if you really want to have fun with terraforming you should make Venus earth-like. I suggest an exciting starting point: build a solar shade at the Lagrange point and block the sun. That would eliminate most of the hard problems with Venus temporarily while we did whatever work is needed to get it spruced up. CO2 freezes to dry ice below -80C or so. You could let through just enough sunlight to get the atmosphere at a pressure humans can survive- then all we need is warm clothes and an oxygen tank.&lt;p&gt;Once Venus is in that state, the problem is simpler- how to get all the carbon and oxygen separated so that the carbon stays in some kind of solid form.&lt;p&gt;Oh, and we&amp;#x27;ll want to go get a load of hydrogen, likely from Jupiter, to mix with that Oxygen to form water. Your fleet of transports moving CO2 to Mars needs to make a detour on the way back.&lt;p&gt;Edit: fixed a word and also lol, just start with building a planet-sized solar shade, says some a-hole on the internet.</text></item><item><author>Teever</author><text>I&amp;#x27;ve wondered about the feasibility of transporting the abundant CO2 in the Venus atmosphere to Mars for the purposes of terraforming both planets at the same time.&lt;p&gt;It&amp;#x27;s been a while since I&amp;#x27;ve done the the envelope math but if I recall correctly there is more than sufficient CO2 on Venus to provide an atmosphere for Mars the issue is just transportation.&lt;p&gt;The last time I thought about it I considered some sort of massive floating solar powered comet builder that would cool the atmosphere into large chunks of dry ice that could then be wrapped in a metal sabot so that the comet could be accelerated to mars via a mass driver.&lt;p&gt;As with everything in space and terraforming the key is scale so the equipment used would need to built in situ out of carbon from the Venusian atmosphere.&lt;p&gt;We are of course still a ways away from mastering self replicating carbon based engineering but the idea of terraforming both planets at the same time is neat to me.</text></item></parent_chain></comment><story><title>Mars Problems vs. Venus Problems</title><url>http://interconnected.org/home/2020/09/23/venus</url></story>