10d
https://phys.org/news/2024-11-ryugu-asteroid-sample-rapidly-colonized.html
Authors report (quote of the actual paper is in the given link, but behind a paywall), that even in "sterile" conditions life is present, which makes the investigation of extraterrestial samples so difficult.
...another consequence of that is that we (humankind) probably brough living cells to the "sterile" environment we want to investigate...
7d 15h
@Ponderable saidWell forensic DNA analysis would show a life form found on say Mars would prove it was life originating on Earth I would think.
https://phys.org/news/2024-11-ryugu-asteroid-sample-rapidly-colonized.html
Authors report (quote of the actual paper is in the given link, but behind a paywall), that even in "sterile" conditions life is present, which makes the investigation of extraterrestial samples so difficult.
...another consequence of that is that we (humankind) probably brough living cells to the "sterile" environment we want to investigate...
My guess is REAL life found on Mars will have DNA unlike anything we ever saw on Earth making it very easy to tell ours from Mars. And it might even have a totally different kind of information storage that our DNA represents, like say a square structure instead of a spiral like our DNA, just to throw out possibilities.
I don't think OUR version of information storage represented by our spiral shape has to be the only way life codes can be made.
It could be a triangular 3D version of our more or less 2D spiral shape for all we know. That to me would be the most exciting development in the history of life chemistry ever if that was found, say on a probe bringing back microorganisms from Europa for instance.
7d 9h
@sonhouse saidProving things is a very difficult endeavour. Even using DNA-tests.
Well forensic DNA analysis would show a life form found on say Mars would prove it was life originating on Earth I would think.
My guess is REAL life found on Mars will have DNA unlike anything we ever saw on Earth making it very easy to tell ours from Mars. And it might even have a totally different kind of information storage that our DNA represents, like say a square str ...[text shortened]... mistry ever if that was found, say on a probe bringing back microorganisms from Europa for instance.
The possibilities to store DAN differently has been explored to some extent. You can look up the very impressive book by Freitas here: http://www.xenology.info/index.htm
7d 6h
@Ponderable saidYes, if life on other planets has a base different from our DNA it might take decades to figure out, like I said the physical structure of our style of DNA might not be the only way bio information can be stored and the chemical tests we use for our DNA might not be able to see what it is until we can crystalize samples to run through advanced electron microscopes and the like to suss out the shape of that life force.
Proving things is a very difficult endeavour. Even using DNA-tests.
The possibilities to store DAN differently has been explored to some extent. You can look up the very impressive book by Freitas here: http://www.xenology.info/index.htm
10h 12m
1 edit
@sonhouse saidBut it is likely that the familiar spiral shape evolved here due to the way the molecules are shaped, which would make it a preferred way the structure would build naturally. The spiral also makes reproduction easy regarding the way the spiral can "unzip" then zip back together. I would suppose these reasons might be why all life in this solar system might most easily evolve in this way.
Yes, if life on other planets has a base different from our DNA it might take decades to figure out, like I said the physical structure of our style of DNA might not be the only way bio information can be stored and the chemical tests we use for our DNA might not be able to see what it is until we can crystalize samples to run through advanced electron microscopes and the like to suss out the shape of that life force.
I mean the bases might be different, but the sheer simplicity of this arrangement might mean any other configuration would be less likely.
This is just off the top of my head, I'd be interested to check out the book Ponderable mentioned.
10h 8m
@divegeester saidMars does seem to be a rather harsh environment to hope that any DNA structure would survive at all, even fossilized.
Any “DNA” deposited on Mars would quickly break down into its component nucleotides, base molecules and be lost.
6h 23m
1 edit
@Suzianne saidThe only hope would be microbes buried say a foot or two underground.
Mars does seem to be a rather harsh environment to hope that any DNA structure would survive at all, even fossilized.
There is a probe on its way to Europa, don't hold your breath🙂 about 5 years to go but it may find some kind of life in the water jets squirting out of the surface.
If they did find some kind of life there, the next step would be a retrieval to get it to advanced labs on Earth. And in 5 or 10 years, the technology of measurement will advance even more than it is now.
Robert Freitas is a clear heavy hitter, so many papers besides his books.
59m
@sonhouse saidWhat do you think of Arthur C. Clarke's warning to "leave Europa alone"?
The only hope would be microbes buried say a foot or two underground.
There is a probe on its way to Europa, don't hold your breath🙂 about 5 years to go but it may find some kind of life in the water jets squirting out of the surface.
If they did find some kind of life there, the next step would be a retrieval to get it to advanced labs on Earth. And in 5 or 10 years, the ...[text shortened]... en more than it is now.
Robert Freitas is a clear heavy hitter, so many papers besides his books.
40m
@Suzianne saidYeah, he said that, and he may have been thinking OUR life forms could attack the native ones and cause an extinction event, but considering even if it turns out say 50 years ago after getting probes down in the water (NASA already is designing little subs that can explore that space) and returned and it was found that it was life based on our same kind of DNA but different sequences, if so, there would be little likelyhood of OUR life forms infecting Europa's alleged life forms.
What do you think of Arthur C. Clarke's warning to "leave Europa alone"?
On the other hand, Clarke may have been thinking about Columbus arriving on that island killing some 90% of the native population because they did not have antibodies to European diseases. But that was human DNA V human DNA, not something that if life was found the most likely to be something so different from our form of DNA it seems to me unlikely we would be able to attack that life form or attack us in reverse. But very strict protocol would be used to keep that sample pristine which I saw during my Apollo days.
19m
2 edits
@sonhouse saidI agree on the protocol being strict. I suspect life is somewhat very similar throughout the cosmos. We keep imagining weird lifeforms in vastly different environments, but I suspect those environments are toxic to life no matter what it looks like. Liquid water, on the other hand, is a basic for some reason.
Yeah, he said that, and he may have been thinking OUR life forms could attack the native ones and cause an extinction event, but considering even if it turns out say 50 years ago after getting probes down in the water (NASA already is designing little subs that can explore that space) and returned and it was found that it was life based on our same kind of DNA but different ...[text shortened]... t very strict protocol would be used to keep that sample pristine which I saw during my Apollo days.