If life existed on Mars (past or present), what are the odds that it is fairly commonplace among the cosmos? If true, it seems virtually impossible to me that there aren't advanced civilizations out there somewhere, especially since there are parts of the universe far older than ours.

https://www.livescience.com/space/mars/incredibly-exciting-nasa-claims-its-found-the-clearest-sign-yet-of-past-life-on-mars

There was this too.

https://phys.org/news/2025-09-potential-biosignatures-ancient-mars-lake.html

We have had a few red herrings previously so this might not pan out but I agree with you.

We are looking for life in our solar system because we can but that is a tiny fraction of our galaxy.

Our solar system is light hours across and the galaxy is 100,000 light years across.

The observable universe is 98 billion light years across containing 10^23 stars so even if life chemistry is ridiculously difficult to get going, the universe has a lot of chances to make it work.

JWST is looking for particular life signatures around exoplanets, I've posted on this previously.

We know deep space can just synthesize organics, from analysis of materials that fall to earth in the form of meteorites and from samples recovered from asteroids.

I think ET is out there, somewhere, it would be cool if he is intelligent and friendly and fancies a visit.

If he is hostile, aggressive and ruthless I hope he is light years distant.

We may find out for sure in another 10-15 years when they finally get some samples back to Earth. Hopefully all of the funding for it won't be cut before then...

17 hours ago, npts2020 said:

If life existed on Mars (past or present), what are the odds that it is fairly commonplace among the cosmos? If true, it seems virtually impossible to me that there aren't advanced civilizations out there somewhere, especially since there are parts of the universe far older than ours.

https://www.livescience.com/space/mars/incredibly-exciting-nasa-claims-its-found-the-clearest-sign-yet-of-past-life-on-mars

I’m getting a bit cynical about NASA’s claims over this. Inorganic processes could be responsible for what they’ve found. But they need the interest to keep the funding.

6 hours ago, exchemist said:

I’m getting a bit cynical about NASA’s claims over this. Inorganic processes could be responsible for what they’ve found. But they need the interest to keep the funding.

If you’re reading Livescience’s story, there’s a bit og embellishment. NASA is a little less bold in its claim

https://www.nasa.gov/news-release/nasa-says-mars-rover-discovered-potential-biosignature-last-year/

“[the sample] contains potential biosignatures, according to a paper published Wednesday in the journal Nature.”

7 hours ago, exchemist said:

Inorganic processes could be responsible for what they’ve found

Have they not ruled out known inorganic pathways?

5 minutes ago, pinball1970 said:

Have they not ruled out known inorganic pathways?

Not according to the report I previously read about it in the Guardian.

As @swansont points out there may be a bit of journalistic exaggeration of what NASA is actually claiming though, so perhaps I’m being unfair.

3 hours ago, pinball1970 said:

Have they not ruled out known inorganic pathways?

In the paper (Hurowitz, J.A., Tice, M.M., Allwood, A.C. et al. Redox-driven mineral and organic associations in Jezero Crater, Mars. Nature 645, 332–340 (2025). https://doi.org/10.1038/s41586-025-09413-0) they have formulated a null hypotheses for abiotic pathways and at least with the data they had, they seem unlikely but it stops short of a full refutation. Form the conclusions:

In summary, our analysis leads us to conclude that the Bright Angel formation contains textures, chemical and mineral characteristics, and organic signatures that warrant consideration as ‘potential biosignatures’^53,54,55, that is, “a feature that is consistent with biological processes and that, when encountered, challenges the researcher to attribute it either to inanimate or to biological processes, compelling them to gather more data before reaching a conclusion as to the presence or absence of life⁵³”. This assessment is further supported by the geological context of the Bright Angel formation, which indicates that it is sedimentary in origin and deposited from water under habitable conditions. Many significant questions remain about the origin of the nodules and reaction fronts encountered by Perseverance. We suggest that further in situ, laboratory, modelling and field analogue research into both abiotic and biological processes that give rise to the suite of mineral and organic phases observed in the Bright Angel formation will improve our understanding of the conditions under which they formed. Ultimately, the return of samples from Mars for study on Earth, including the Sapphire Canyon sample collected from the Bright Angel formation, would provide the best opportunity to understand the processes that gave rise to the unique features described here.

On 9/12/2025 at 1:32 AM, exchemist said:

I’m getting a bit cynical about NASA’s claims over this. Inorganic processes could be responsible for what they’ve found. But they need the interest to keep the funding.

It seems to me that if there are signs of life in meteorites, it is likely to be a pretty commonplace occurrence throughout the cosmos even if that is still speculative. Whether that life somewhere could be "intelligent" is even more speculative but still probable IMO. Whether any of that life has ever traversed the universe to arrive at planet Earth through means other than the aforementioned meteorites is possible but seemingly highly improbable knowing how long it takes the fastest moving thing we know of (light) to get here and the length of life of even the longest lived higher organisms on Earth. If both of those things can be overcome, somehow, then it seems probable we have been checked out by aliens.

2 hours ago, npts2020 said:

It seems to me that if there are signs of life in meteorites, it is likely to be a pretty commonplace occurrence throughout the cosmos even if that is still speculative. Whether that life somewhere could be "intelligent" is even more speculative but still probable IMO. Whether any of that life has ever traversed the universe to arrive at planet Earth through means other than the aforementioned meteorites is possible but seemingly highly improbable knowing how long it takes the fastest moving thing we know of (light) to get here and the length of life of even the longest lived higher organisms on Earth. If both of those things can be overcome, somehow, then it seems probable we have been checked out by aliens.

Oh I agree it seems most improbable that our planet is the only one in the cosmos with life. However there have been no signs of life in meteorites, so far as I am aware. There been signs of certain building blocks of our biochemistry (precursors of nucleotide bases) which could explain how they came to be available on earth, but that’s about it, at least according to what I have read.

3 hours ago, exchemist said:

Oh I agree it seems most improbable that our planet is the only one in the cosmos with life. However there have been no signs of life in meteorites, so far as I am aware. There been signs of certain building blocks of our biochemistry (precursors of nucleotide bases) which could explain how they came to be available on earth, but that’s about it, at least according to what I have read.

Sure, but if it quacks like a duck...

I just don't see why an alien civilization would want to have anything to do with a species like humans that appear to be knowingly headed toward self destruction.

6 hours ago, npts2020 said:

Sure, but if it quacks like a duck...

I just don't see why an alien civilization would want to have anything to do with a species like humans that appear to be knowingly headed toward self destruction.

Water & an atmosphere perhaps?

Are we as humans not also doing the same thing?

Maybe we are alien to earth because https://www.space.com/37562-a-huge-asteroid-hitting-mars-4-billion-years-ago-may-have-shaped-the-red-planet.html

Iirc, Mars cooled down before the earth due to it's size & may have satisfied conditions for certain life to form before it got smacked by an asteroid, sending quite a lot of asteroid/Martian fragments inwards & outwards.

Perhaps our very long lost ancestors were on one or perhaps a few of those fragments.

Maybe life came from the asteroid itself.

Edited September 14Sep 14 by Imagine Everything

6 hours ago, npts2020 said:

Sure, but if it quacks like a duck...

Are precursors of nucleotide bases the quacking of a duck, or just some random sound? Seems like finding carbon in a meteorite could be considered a quack as much as finding a precursor of a nucleotide base is considered a quack.

7 hours ago, npts2020 said:

Sure, but if it quacks like a duck...

I just don't see why an alien civilization would want to have anything to do with a species like humans that appear to be knowingly headed toward self destruction.

It doesn’t quack. These are heterocyclic compounds containing nitrogen, thought to be formed inorganically in deep space on cold bodies containing carbon and ammonia. They are not evidence of life elsewhere. But they are possible sources of key molecules for the start of terrestrial life.

Edited September 14Sep 14 by exchemist

Couldn't panspermia from another planet in the solar system skew the data if we find life anywhere else in the solar system? Unless said life is significantly different from the life we have on Earth how would we show any life detected on Mars didn't come from Earth? Or even show life on Earth couldn't have come from Mars? I'm not sure that finding life elsewhere in the solar system is a good way to plot data points.

On 9/14/2025 at 1:04 PM, exchemist said:

It doesn’t quack. These are heterocyclic compounds containing nitrogen, thought to be formed inorganically in deep space on cold bodies containing carbon and ammonia. They are not evidence of life elsewhere. But they are possible sources of key molecules for the start of terrestrial life.

I never claimed otherwise, was merely agreeing that is possible those compounds could show life has existed other than on planet Earth. The second part about aliens visiting us wasn't meant to be connected to any commentary about life on Mars, just speculation about why any advanced civilization would be interested in us other than pure scientific curiosity. (I don't buy the resource argument, it is hard to imagine an out-of-the-way place like ours would be the closest or easiest way for them to get what they want)