Life could possibly exist in the clouds of Venus. It’s a stunning discovery, especially since Venus was pretty much written off as a ‘dead planet’, with a surface temperature of 464ºC (867ºF). In addition, the surface of Venus has 92 times the atmospheric pressure of Earth, like the equivalent of being 3,000 feet underwater. That makes the discovery of phosphine gas, known to exist only through a bi-product of life, all the more remarkable.
Venus is closer to Earth than Mars, and is the second brightest object in the night sky, after the moon. The discovery seems to have caught a number of experts off guard, and is sure to ignite a newfound enthusiasm for ‘Earth’s Sister’.
Any potential life would be microbial in nature, somehow existing in sulfuric acid clouds above the surface. Even still, it would change the course of life on this planet profoundly, and open up millions of questions for the universe.
The discovery is described well by Vox, who also interview one of the chief scientists behind the discovery. We’ve captured some of their interview below.
“We did exhaustively search through all known chemistry … and we didn’t find anything that could produce more than the tiniest amount of phosphine in Venus’s atmosphere,” says MIT planetary scientist Sara Seager, who was one of the co-authors on the discovery published in Nature Astronomy, says. That leaves us two possibilities: The gas was created by life or by some chemical interaction scientists don’t yet know about.
Brian Resnick
To start off: What’s the gist of the discovery that you and the team announced this week?
Sara Seager
We aren’t claiming we found signs of life. We are claiming we have a robust detection of the gas phosphine in the atmosphere.
[After searching] all the known chemistry — volcanoes, photochemistry, lightning — we didn’t find anything that could produce more than the tiniest amount of phosphine in Venus’s atmosphere. So we’re left with two possibilities. One is that there is some kind of unknown chemistry, which seems unlikely. And the other possibility is that there’s some kind of life, which seems even more unlikely. So that’s where we’re at. It took a long time to accept it.
Brian Resnick
As I understand it, if life exists on Venus, it wouldn’t be on the surface of the planet, but in its sulfuric acid clouds?
Sara Seager
It’s always been the theory because the surface is too hot for complex molecules.
Brian Resnick
What is too hot? What happens there?
Sara Seager
Molecules break apart. If you took a protein or an amino acid, or anything, and put it in high temperature, it would come apart into smaller fragments and atoms.
Brian Resnick
Why, then, is the atmosphere a better place to look for life?
Sara Seager
It has the things that astrobiologists think life needs. It needs a liquid of some kind. And there is liquid in the atmosphere, although it is liquid sulfuric acid.
Life needs an energy source. So there’s definitely the sun, at least as an energy source. Life needs the right temperature. In the atmosphere, there is the right temperature. And life needs a changing environment to promote Darwinian evolution. So if you want to break it down like that, that’s why. To simplify, it’s mostly the temperature argument. Temperature and liquid.
Brian Resnick
Do we know of any life form on Earth that can exist in liquid sulfuric acid?
Sara Seager
No, we don’t.
Brian Resnick
What makes it seem possible for life to exist in sulfuric acid?
Sara Seager
We simply don’t know. I think your questions are the next decades of research, basically.
An artist’s rendering of Venus’ volcano covered surface. It’s not a hospitable place, by any means.
