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A comment on Phosphine detected in the atmosphere of Venus – an indicator of possible life?. Parent comment

Re:Phosphine detected in the atmosphere of Venus – an indica... by pc86 on Monday September 14, 2020 @01:35PM (#24472794)
I don't mean this as a counterpoint to your argument, which I think is a valid one, or as any kind of sarcasm. But even as a relative layperson as far as these things go (1 college semester each of bio and o-chem, which I didn't do all that well in) I would be extremely interested in learning about any bacteria that could a) survive on Earth at a large enough scale to find its way onto a Soviet spacecraft; b) survive a trip through space; c) not only survive but thrive on Venus so much so that it reproduces enough for us to pick it up now.

Hopefully if they can get a probe out there they would be able to tell definitively if it was Soviet contamination or not, although I'm not sure how they would be able to do that. I could see them ruling it out (some entirely different DNA structure or something) but not sure how they'd say 100% that it was Soviet in origin.

[ Parent | on HN ]
Re:Phosphine detected in the atmosphere of Venus – an indica... by kortex on Monday September 14, 2020 @04:08PM (#24474521)
I have a degee in chem. Your intuition is spot on. Lets assume Venera 3 wasn't sterilized (reports in 1966 say it was [1] but the effectiveness is contested [2]).

Even if spores did survive the space trip (actually quite plausible, [0], venus trip is ~110 days), the atmosphere is extremely dessicating and acidic (SO2, SO3, H2SO4), and the ground is too hot for any known life. The dessication and osmotic pressure is the real kicker. It's very unlikely spores would germinate without rehydration.

[0] https://www.nasa.gov/mission_pages/station/research/news/eu_...

[1] https://www.nytimes.com/1966/03/06/archives/soviet-says-venu...

[2] https://www.jstor.org/stable/1720963

[ Parent | on HN ]
Re:Phosphine detected in the atmosphere of Venus – an indica... by saberdancer on Monday September 14, 2020 @03:43PM (#24474264)
Exactly. I do not think that contamination by Venera probes is likely suspect. The atmosphere of Venus has no oxygen and most life on Earth needs oxygen. Even extremophile life on Earth isn't extreme enough for Venus so it would be extraordinary set of circumstances that Venera probe is contaminated with just the right type of bacteria that is then able to adapt to Venus and spread planetwide.
[ Parent | on HN ]
Re:Phosphine detected in the atmosphere of Venus – an indica... by pvg on Monday September 14, 2020 @03:43PM (#24474263)
On the first two, bacteria are pretty much ubiquitous and constitute a significant chunk of total biomass on Earth. They can form spores some of which are exceptionally sturdy. It's not too hard to imagine some sort of conditions in which c) can happen - you sent a yeast probe to a sugar water ocean planet but that doesn't sound too much like Venus.
[ Parent | on HN ]