Terraforming Venus #1

So, like my first post, this one is going to focus on Terraforming one of the planets in our solar system. I think that I'm going to make this a regular thing because it's such a large topic that I can't tackle it all in one post. I'd like to apologize, as my sister did in her last post as well, for not posting more content sooner, I'm going to do my best from now on to post at least once every two weeks, if not more.

One of the major issues with Venus when it comes to sustaining human life is the incredible heat that envelopes the planet. Even though it's covered in reflective water vapor clouds, it also traps quite a bit of the heat that comes from the Sun. This has been termed a runaway greenhouse effect because of the excess of carbon dioxide (the Venusian atmosphere is composed of 90-95% CO₂) and other chemicals in the atmosphere on Venus that trap the heat. There are many ways to go about turning down the heat on our sister planet, and I'll examine a few of these ideas, some of them my own.

My first concern with Venus is that its slow rotation may be one of the causes of this excess heat buildup, one side faces the sun too long, and the winds on the planet carry the heat around. I'll explore specific solutions to the rotation problem in a follow up post, but generally the idea is that somehow Venus needs to be made to have close to a 24 hour period of rotation in any case for permanent human habitation on the surface. The major issue with this is that the energy required for such a feat would be enormous. Venus has a backwards, though almost non-existent, rotation, along with a mass nearly the same as that of Earth, which means that to significantly increase its rotation speed, in either direction, an extremely large force must be used. If there was no rotation issue the heat transferred to the planet might differ and the planet might cool off.

Another solution would be to move Venus into a slightly higher orbit. This would mean less energy from the sun getting to Venus and therefore cooler temperatures. The problem with this is that orbital dynamics would change in the solar system dependent on how far Venus is moved. Though the interactions between planets isn't that large, it could still impact the paths of asteroid and send them hurtling where we'd prefer they wouldn't. Also getting the planet to stay in a roughly circular orbit may prove difficult, and again the energy required is absurd.

An easier idea to carry out would be some sort of sunshade for the planet. By blocking out a significant portion of the light hitting the planet with some sort of barrier or orbiting debris of some kind the energy heating up the planet would reduce and cooling would take place, though it might take some time. Problems with this idea include the question as to where such a massive amount of material to block out the sun would come from. Also if it were only enough to block the sun from one side, placing it in orbit would mean that it wouldn't do its job 100% of the time. I once saw an idea to prevent more global warming on the Earth by launching millions of tiny lenses that would filter out the light hitting the Earth as they orbited around. Such an idea may work for Venus, but the cost is unknown and probably astronomical by today's standards.

Another idea may be that the heat could be converted into other forms of energy. Thermo-electric generators, though they aren't the most efficient, have the ability to turn differences in temperature into electrical output. Water could be turned into steam to power turbines, and many other possibilities like orbital solar power (which may also block some sun) could all lead to cooling down Venus, though probably over a significant period of time.

These solutions are absurd and on an incredibly large scale, but that makes sense when you're talking about terraforming. When I think of terraforming I'm imagining future technologies and capabilities that won't likely come around until at least a century from now. But I feel that thinking ahead on these issues may prove useful, so that we can judge the best ideas and when we do reach planets outside of the solar system we're prepared to make them habitable.