Hello, friends!
Over the last decade or so, Mars has been trying really hard to convince us that he can (and does) support life. We’ve seen evidence of liquid water on the Martian surface, and traces of methane have been detected in the Martian atmosphere. These things are highly suggestive, but none of that proves Martian life exists.
It would be nice if we knew of a chemical that clearly and unambiguously proved that a planet has life, wouldn’t it? According to this paper published in Nature Astronomy, phosphine (chemical formula PH3) might be the clear and unambiguous biosignature we need. Here on Earth, phosphine gas is a waste product produced by certain species of anaerobic bacteria. It’s also produced by humans in our factories. Either way, the presence of phosphine in Earth’s atmosphere is strong evidence that there’s life on Earth.
And according to that same paper from Nature Astronomy, astronomers have now detected phosphine on another planet. No, it wasn’t Mars.
Okay, we humans do know of non-biological ways to make phosphine, but they’d require Venus to be a very, very different planet than she currently is. For example, Venus would need to have a hydrogen-rich atmosphere, or Venus would have to be bombarded constantly with phosphorus-rich asteroids, or the Venusian surface would have to be covered with active volcanoes (more specifically, Venus would need at least 200 times more volcanic activity than Earth).
None of that appears to be true for Venus, so we’re left with two possibilities:
- There is life on Venus.
- There’s something we humans don’t know about phosphine, in which case phosphine is not the clear and unambiguous biosignature we hoped it was.
In either event, Venus is about to teach us something. Maybe it’s a biology lesson. That would be awesome! Or maybe it’s a chemistry lesson. Personally, I’m expecting it to be a chemistry lesson. There must be some other way to make phosphine that we humans never thought of.
P.S.: Now I’m sure a lot of you are thinking: “Wait a minute, don’t Jupiter and Saturn have phosphine in their atmospheres too?” You’re right. They do, and we’ll talk about that in Wednesday’s post.
Planet Pailly 
We may all have a touch of phosphine fever right now.
LikeLiked by 3 people
Yeah, we kind of do. Or at least I do. I don’t want to get my hopes up too much, but whatever’s happening on Venus is really exciting!
LikeLiked by 3 people
Phosphine every day helps you work rest and play! We’re lucky we have what we need on earth because so far no visitors and maybe thats a good thing.
LikeLiked by 3 people
Maybe it is.
LikeLike
This is really cool!
Also, I love your little cartoons. They’re so cute!
LikeLiked by 2 people
Thank you so much!
LikeLiked by 1 person
I thought Venus was known to have a lot of volcanism. Although maybe not 200 times what Earth has, and maybe not as recent as it’d need to be for what we’re detecting.
LikeLiked by 2 people
That was the first bit of fact checking I did after reading that Nature Astronomy paper, because I thought we had recently discovered Venus does have active volcanos. Apparently that’s not confirmed yet, and even if it were, it sounds like it’s a very small number of volcanos.
Venus’s surface is surprisingly smooth, which means it must have been paved over (so to speak) with fresh lava fairly recently. But that’s recently in geological terms. Something would have to keep producing phosphine on a daily basis to explain the amount of phosphine in Venus’s atmosphere.
LikeLiked by 2 people
Thanks. That’s what I suspected.
That said, sometime after I made this comment, I came across a tweet to this paper.
https://arxiv.org/abs/2009.11904
I’m not versed enough in planetary science to evaluate it. And it’s a hypothesis in a preprint, so caution is warranted.
LikeLiked by 2 people
I just skimmed through the paper you sighted. I’ll read it more thoroughly later. My first impression is that it sounds like a plausible enough hypothesis, but I wish there were harder evidence of active volcanos.
On the other hand, if possible life and possible volcanos end up being the only available explanations, I think Occam’s razor would tell us to go with the volcanos.
LikeLiked by 3 people
I think this will be a chemistry lesson too – but either way we need to understand it.
LikeLiked by 2 people
The last big chemistry lesson Venus taught us demonstrated what chlorine and fluorine can do to a planet’s ozone layer. So even if it’s just a chemistry lesson, this phosphine thing may be important for reasons we can’t yet understand.
LikeLiked by 1 person
Well it’s important in one sense that it’s no longer an unambiguous treat for microbial life
LikeLiked by 2 people
Very true.
LikeLiked by 1 person
Wow , thats so cool
LikeLike