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We can terraform Venus, it is not that difficult. Venus is extraordinarily hot, and has a very thick atmosphere. The pressure and temperature on the ground are
by credit_guy 2y ago
We can terraform Venus, it is not that difficult. Venus is extraordinarily hot, and has a very thick atmosphere. The pressure and temperature on the ground are both immense. But there's an intervention that we can perform that is close to our current technological capabilities. If we put a large sunshade in front of Venus, so we decrease the amount of light that comes from the Sun and hits Venus, then we can cool off the planet. If we cool it to -80 °C the CO2 from the atmosphere will freeze and turn into dry ice and fall and settle on the ground. The remaining part of the atmosphere will be N2, at roughly the same pressure as on Earth. The albedo from the dry ice could be enough that the solar shade might not be needed anymore.
How much would such a sun shade weight? Current solar sails weigh between 3 and 5 grams per m2, so 1g/m2 is probably possible in the near future. That is one ton per km2. The radius of Mars is 6000 km, so the area of the cross-section is about 100 million km2. To obscure a few percent of that would take a few million tons of material. That's a lot, but a million ton is the cargo capacity of 5000 Starships. It's not completely impossible.
- newsuser 2y agoCarl Sagan proposed something along the lines in 1961 (but using bacteria to convert CO2 to graphite), however later it became clear that wouldn't work, in part, because the depth of the created sediment layer would be >100 meters. https://en.wikipedia.org/wiki/Terraforming_of_Venus https://en.wikipedia.org/wiki/Terraforming_of_Venus
- actionfromafar 2y agoWhat's wrong with a 100 meter sediment layer? Edit: apparently, as per Wikipedia, in the high pressures of Venus, the resulting pure oxygen atmosphere would combust the solid carbon sediment, going straight back to the same carbon dioxide atmosphere is has now.
- Maxamillion96 2y agoor you could just direct an asteroid of the right size into that location.
- xattt 2y agoYou first.
- credit_guy 2y agoI'd like to think so, but most likely not. This is an old idea of mine, I wrote a comment about it here on HN a few years ago, before ChatGPT was a think. But now that ChatGPT exists, I asked it what it thinks. And to my surprise, it mentioned solar shades, so there is a chance it found this idea in its training.