Atmospheric analysis shows Venus never had Earth-like life, scientists say
40 points
23 days ago
| 4 comments
| theguardian.com
| HN
credit_guy
20 days ago
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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 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.

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newsuser
19 days ago
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Carl 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

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actionfromafar
19 days ago
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What'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.

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Maxamillion96
19 days ago
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or you could just direct an asteroid of the right size into that location.
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xattt
20 days ago
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You first.
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credit_guy
19 days ago
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I'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.
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ilrwbwrkhv
20 days ago
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We should still be looking at Venus cloud cities, they are much better than Mars, with at least as a magnetosphere.
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kirykl
20 days ago
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ultimately we need to move away from the Sun not closer
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gambiting
20 days ago
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If by "ultimately" you mean "in the next few hundred million years" - sure. But that's an absolutely nonsensical time scale to be worrying about when we're at a stage where we can barely escape Earth's orbit.
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rqtwteye
20 days ago
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We have a few hundred million years before we need to worry about the sun.
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GenerocUsername
23 days ago
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Venus dry now. Venus dryness not changing. Therefore Venus always dry. Therefore Venus never had earth like life
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jvanderbot
20 days ago
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Venus planetary science (Venusian?) lacks the abundance of in-situ data that Mars has. We'll know more in a decade.
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dylan604
20 days ago
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What new tech have they used to allow the in-situ data to be obtained that allows the lander to not be crushed/melt on the surface?
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jvanderbot
20 days ago
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Crushing is manageable but melting is the issue. At this point all planned missions are still orbiters, so Venus will still not have the wealth of in-situ data that Mars does.

There are two major concepts that I found really fun: 1) airships and 2) steampunk rovers.

Airships:

2018 JPL: https://science.nasa.gov/resource/aerial-platforms-for-the-s...

2020s report on in-situ sampling using airships as mothership https://kiss.caltech.edu/final_reports/Venus_In_Situ_Final_R...

Clockwork rover for long-lived venus exploration: https://www.jpl.nasa.gov/news/a-clockwork-rover-for-venus/

I don't think that last one was (too) serious, but it was interesting to sus out the costs/benefits at TRL1-2 at least.

AGU is a fairly open, very accessible conference for tracking progress on these. Here's a short paper on venus long lived surface missions.

https://arxiv.org/pdf/1611.03365

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tivert
20 days ago
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> Clockwork rover for long-lived venus exploration: https://www.jpl.nasa.gov/news/a-clockwork-rover-for-venus/

STRANDBEEST EVOLUTION 2021: https://www.youtube.com/watch?v=C97kMKwZ2-g

Screw Venus, they need to work on adding mechanical computers to these Strandbeests, so they can turn around and wander the world's beaches autonomously for years at a time.

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pantalaimon
20 days ago
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Are there any probes planned?
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jvanderbot
20 days ago
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Yes! Venus just got a lot of attention lately, when it was clear Mars priorities were declining.

https://nssdc.gsfc.nasa.gov/planetary/planets/venuspage.html

    DAVINCI - NASA Venus Flyby and Probe (2029)
    VERITAS - NASA Venus Orbiter (2031)
    EnVision - ESA Venus Orbiter (2031)
Davinci: https://ssed.gsfc.nasa.gov/davinci/

Veritas: https://www.jpl.nasa.gov/missions/veritas/

EnVision: https://www.esa.int/Science_Exploration/Space_Science/Envisi...

That davinci page is pretty cool!

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kulahan
20 days ago
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Yes, they cover this in the article. Flyby + probe.
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anacrolix
19 days ago
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Shaq big man man but he not dumb
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risenshinetech
20 days ago
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The article absolutely does not support the claim made in the title. Either the writer did an awful job of summarizing the findings, or the findings are very weak.
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LegionMammal978
20 days ago
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The paper's arguments [0] are from climatic modeling. When Venus formed, it had lots of water in its interior. If its magma oceans cooled very slowly, most of the water would have escaped into space. But if its magma oceans cooled quickly, there may have been liquid water on the surface at some point, and there would have also been lots of interior water left. This interior water wouldn't have much chance to escape, even after the surface water boiled away.

They found that there's very little hydrogen present in its volcanic gases, suggesting that it doesn't have much interior water, and that it didn't in the past, which precludes the formation of surface oceans. It's not incontrovertible proof (something we'll most likely never have), but it's still solid evidence against oceanic life.

[0] https://www.nature.com/articles/s41550-024-02414-5

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Teever
20 days ago
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But how can they rule out the water leaving the planet very quickly after a long time of Earth Like conditions?

It's been a while since I took a solar system geology course but IIRC Venus undergoes periodic planet wide resurfacing events that wipe out the geological record.

I'm not sure if we can tell when those events started happening. It's entirely plausible they only started happening recently (geologically speaking) which possibly would not show up in the gas analysis.

Again, I'm no expert.

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kulahan
20 days ago
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Huh? They specifically said, in a quote from the article, that it rules out Earth-like life. It’s too dry to have supported that kind.
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