Possible clues to past life on Mars identified in rocks found by rover | Detailed image analysis of speckled rocks found by the Perseverance rover has confirmed a “potential biosignature.”

>confirmed a “potential biosignature”

It’s definitely maybe perchance a sign of something we can’t say *isn’t* perhaps not life

Astronomer here! What an exciting day and intriguing result!

So, the first thing to note about looking for life is it’s not like in the movies, where the saucer abruptly touches down and no one can argue aliens exist. In reality, it’s a lot more complicated and we have to look for what are called biosignatures- things that, as far as we know, are *only* produced by life. The trouble is it’s not as simple as “ah that only is produced by life, case closed!”- people can misidentify what the thing is (because science is hard, and a lot of molecules are very similar but not quite the same), and often signatures can be produced by life *or* non-life processes- what’s more, it might be the case that *on Earth* only life produces a biosignature, but in a universe of options other mechanisms can create the biosignature.

So, in short, it’s not as cut and dried as it is in a Hollywood movie to say “yes, I’ve found evidence of life!” Instead, a better way to think of it is water on Mars- when I was a kid, the idea of water on Mars was not at all thought to be true. But then one rover found some signature that indicated there might have been water, and another experiment found slightly more evidence… and today it’s commonly accepted that Mars had giant liquid *oceans* in its past, and [liquid water flows sometimes on the planet!](https://www.nasa.gov/news-release/nasa-confirms-evidence-that-liquid-water-flows-on-todays-mars/) This took years and years for scientists to find enough evidence to prove it, which is not as dramatic but *is* in line with the scientific process.

So with all that, today’s result! Perserverence, a Mars rover, has found signatures of carbon-based compounds and minerals on rocks that, on Earth, are signs that microbial life exist- specifically, [vivanite](https://en.wikipedia.org/wiki/Vivianite) and [greginite](https://en.wikipedia.org/wiki/Greigite). ([Full paper here!](https://www.nature.com/articles/s41586-025-09413-0)) *SOMETIMES* you can get these minerals created not because of microbial life, and the TL;DR of it all is from the rover data alone we can’t figure out if the minerals are there because of microbial life interactions, or a non-life process. (This is outside my wheelhouse, but my understanding is more careful analysis of a rock in a lab on Earth, say, would tell you more about the formation of said rock and if microbes were involved.) So- big deal! First time we’ve found a solid potential biosignature, and arguably the best evidence so far that life used to exist on Mars! But not a smoking gun just yet to say “life on Mars!”

Finally, it’s worth pointing out that right now as it stands the NASA planetary budget is going to be slashed so hard it’s difficult to imagine we would be able to follow up on this, and the Perseverance rover itself for example is facing over a 20% cut on its budget. The deadline is the end of the month for the government to pass the continuing resolution that will include NASA/NSF/ everyone else who funds science, so *please* keep the pressure on with your Congressional reps!

Same old story we’ve heard from EVERY Mars lander/rover mission.

Anyone have a non-paywalled article?

“confirmed potential”

Funny combination of words.