Re:Why is Venus hell and Earth an Eden?
by Symmetry on Monday September 22, 2025 @10:45AM
(#45334200)
A big issue is that neither seem to have developed photosynthetic life[1] and without a lot of oxygen in the atmosphere they don't have an ozone layer. That means that UV light penetrates further and breaks up water into its constituent parts allowing the light hydrogen to be blown away by the solar wind over geological time scales.
[1] It's looking increasingly plausible that Mars developed primitive life, but I'd bet heavily against photosynthesis. That took way longer than chemosynthetic life on Earth.
Re:Why is Venus hell and Earth an Eden?
by glenstein on Monday September 22, 2025 @11:02AM
(#45334460)
I think the article speaks to the point you're making also, that the UV light may have been an important (if not primary) mechanism for blasting away Venus' water. So even if someone snapped their fingers and made Venus perfectly terraformed, it probably once again would begin the process of losing its water. And any life would have to survive a brighter sun.
The article mentioned something about heavy water which I don't understand very much. But it's a problem.
The tragedy of both Mars and Venus is that billions of years ago? It seems like they both might have had abundant liquid oceans of water. Which doesn't mean they would have supported life, but they would have been so much closer to habitable and a much better starting point. Instead, it's like if you're deadbeat brother house-sat them for a weekend and threw a bender and trashed the houses, that's what we're left with now.