Potentially dumb question, but I keep reading that the average surface temperature of Venus is 450C and so completely hostile to life, but didn't we discover recently that the poles are much colder? [1] Aren't there thus regions on the surface with similar temperatures to earth?
I think the comparison was to 0..100C - liquid water on Earth surface.
Boiling point depends on atmospheric pressure. On Venus (93 bar) melting point is about 0C [1] and it boils at 305.6C. Interestingly under pressure "water becomes less polar and behaves more like an organic solvent such as methanol or ethanol" [2].
The other place where life could exist is in the upper atmosphere where apparently temperatures are much more hospitable. There's a really good write-up with more information here [1]. On earth there exists microorganisms that live in our atmosphere so one hypothesis to explain the phosphine is that there may be a similar situation on Venus. I believe its also been theorized that we could build floating cities on Venus [2] given the climate in the upper-middle atmosphere.
In fact the atmosphere of Venus is the only place outside of Earth where humans could walk outside with just a simple oxygen mask - about 50km above the surface the temperatures are around 0-20C and pressure of one atmosphere. No other celestial body in our solar system has anywhere like that. But it's just like this article correctly identified I think - floating cities on Venus are not as cool as "normal" cities on Mars.
> the atmosphere of Venus is the only place outside of Earth where humans could walk outside with just a simple oxygen mask
Surely a bit of an exaggeration? The mostly carbon dioxide, 1 atm of pressure area is not bad, but it coincides with the thickest cloud coverage. The clouds which are composed of sulfuric acid.
A new novel by Derek Kunsken called "House of Styx" explores in detail human habitation of Venus. In floating cities and airships and realistically dealing with pressures, temps, and the acidity of the atmosphere.
I assume the atmosphere microorganisms on Earth started in a terrestrial tidal pool though and evolved from there. There’s the rub for thinking about atmosphere organisms existing on other planets.
Right, I wont even pretend to be an armchair expert on this just regurgitating what I've read. Long and short of it is we have no idea but from what I recall the original paper was very thorough in trying to explain the phenomenon and life was the most likely hypothesis given what we know. Regardless of the origin it sounds like there is some new science to be found which is exciting.
Oh I did not think about that or know that. That’s true.
“Recent studies from September 2019 concluded that Venus may have had surface water and a habitable condition for around 3 billion years and may have been in this condition until 700 to 750 million years ago.”
Do microorganisms spend their entire lives in Earth's atmosphere, or are they simply found there? It doesn't seem surprising that some would find their way up there, but I have a hard time imagining how microorganisms could maintain a certain altitude. On land, they can anchor themselves to hospitable environments to breed, but in the atmosphere, how could they find one another?
Apparently they do live in the upper atmosphere. [1].
> Although many of the organisms borne aloft are likely occasional visitors to the upper troposphere, 17 types of bacteria turned up in every sample. Researchers like environmental microbiologist and co-author Kostas Konstantinidis suspect that these microbes may have evolved to survive for weeks in the sky, perhaps as a way to travel from place to place and spread their genes across the globe. "Not everybody makes it up there," he says. "It's only a few that have something unique about their cells" that allows them survive the trip.
To the best of our understanding, the surface of Venus is isothermal, meaning that there is little variability in temperature, whether on the pole or equator, day or night. That 2016 rash of articles about "cold poles" on Venus were rather misleading interpretations of a single scientific paper about a measurement from the upper atmosphere.
[1] https://astronomy.com/news/2016/04/esa-finds-a-frigid-surpri...