Here's a long-form article about this that appears tomorrow in Earth & Sky. It was apparently published early by accident, and taken down; hence this Google cache link.
https://webcache.googleusercontent.com/search?q=cache:dUWrpm...
https://webcache.googleusercontent.com/search?q=cache:dUWrpm...
Simply put, a gas that shouldn’t be there, and on Earth is considered a conclusive biosignature: phosphine, a very stinky gas. As far as scientists know, there are only two ways to produce it, either artificially in a lab, or by certain kinds of microbes that live in oxygen-free environments. Since it is rather unlikely there any alien labs on Venus, that leaves microbes."
Or it reveals, that we still don't really know what is going on on venus, which chaotic atmosphere and vulcanic activity might very well result in the specific "lab conditions" to create phosphine.
So, it is a very interesting find, worth investigating, but I just for the existence of a gas, I would not shout "proof of alien life", yet.
> As far as scientists know, there are only two ways to produce it, either artificially in a lab, or by certain kinds of microbes that live in oxygen-free environments.
https://en.wikipedia.org/wiki/Phosphine
Philippe Gengembre (1764–1838), a student of Lavoisier, first obtained phosphine in 1783 by heating phosphorus in an aqueous solution of potash (potassium carbonate).[4][5]
The second preparation method in Wikipedia looks more plausible https://en.wikipedia.org/wiki/Phosphine#Laboratory_routes
> 4 H3PO3 → PH3 + 3 H3PO4
> Phosphine evolution occurs around 200 °C (400°F).
But I only have a Chemistry specialization in my secondary school and I am not an astrogeologer.
Even if this were the case, it would still be quite amazing.
That would be a amazing sensation. Terraforming would then be much, much easier, than expected. But I doubt it.
I think it was maybe Carl Sagan who said (something like): if we find life in our solar system it's probably game over for us, as it means the great filter is likely ahead of us, not behind us.
Though, you can take one look at the world right now, and not see how easy it would be to just destroy it if we aren't careful (and we're not being careful).
Though it's quite possible that if there is something on Venus or Mars it's Earth-origined, since conditions here 4 billion years ago look better for abiogenesis.
If there are several filters, then they may differ in effectiveness by many multiples, and then it's semantics as to whether you say any beyond the largest are "great".
I think a more interesting concept would be exchange of microbes between Venus and Earth at some point in their distant past, and then could we might be able to date that (those) event (s) via their molecular clocks (https://en.m.wikipedia.org/wiki/Molecular_clock)