• Welcome! The TrekBBS is the number one place to chat about Star Trek with like-minded fans.
    If you are not already a member then please register an account and join in the discussion!

Curiosity finds "organic matter" and methane on Mars!

Romulan_spy said:
I am pretty sure organic material and methane are strong signs of life.
Click to expand...
Pessimistic hat on: Organic just means carbon chemistry, which is not necessarily associated with biological processes. Geologically, methane can be produced by heating olivine in the presence of water and carbon dioxide.

https://www.nature.com/news/2005/050531/full/news050531-10.html

Optimistic hat on: One of the Viking lander probes' experiments (labelled release) detected signs of possible life but this evidence was rejected because of negative readings from other experiments (gas chromatograph and gas exchange) and inorganic mechanisms were proposed for the "false positives". However, the subsequent discovery of perchlorate in Martian soil could explain the negative results.

Perhaps not so false after all, it seems. We need to dispatch modern experiments for testing for life on Mars. Unlikely to be anything more advanced than archaea or bacteria, of course. Eukaryotic life forms are way too complex to have developed as they seem to have evolved with very low probability on Earth.
 
Last edited:
Oh I would love for this to be life, and life to be found to be a natural consequence of broadly accommodating conditions, and this was the case almost everywhere.
 
Asbo Zaprudder said:
Optimistic hat on: One of the Viking lander probes' experiments (labelled release) detected signs of possible life
Click to expand...
I just read up on it. Much more fascinating than I remember.

Since ‘labelled release’ sounded a bit like ‘press release’ to me, this must to be added: They literally released nutrients in which individual carbon molecules were labelled using a radioactive isotope, then detected the labelled atoms inside radioactive carbon dioxide molecules. That result seems to be pretty significant to me. I'm not sure if I'm reading Wikipedia correctly, but the information is cited on the pages of both probes, implying the same result came from both Viking probes?

The gas spectrometer tried to find organic compounds in the soil by heating to a gas, however the amount of perchlorate detected by Phoenix would have undoubtedly destroyed the organic molecules when heated. So the Phoenix findings rendered any non-detection by the spectrometer moot.

I do remember that before NASA released the perchlorate finding, the White House had to be briefed, and had to wait heads up. At the time I was totally confused why finding bleach byproducts on Mars would require consulting the president. I now realise they've basically discovered that Viking seems to have discovered life.

Main reason to not to be too optimistic is that, well, like the perchlorate caused misinterpretation, sending a lab of a few tricks to Mars, without the ability to do a proper exhaustive analysis in-situ, is unreliable.

Also the probes didn't detect anything consuming oxygen, CO₂, methane or hydrogen gases, which seems to have nothing to do with the perchlorate?
 
Last edited:
^That's why more current technology is required or a sample-return mission or direct on-site investgation by a manned lab. However, we might well contaminate or destroy any fragile ecosystem if man finally makes it to the Martian surface. Do we care if we see Mars as a potential lifeboat for human DNA?

The BBC news site has a more detailed article about the latest findings:

Curiosity rover sees seasonal Mars methane swing - http://www.bbc.co.uk/news/science-environment-44405658
 
OK, local fake news here are already reporting that life was found on Mars. ‘Organic matter’ gets replaced with ‘signs of life’ (which is already a stretch), then that gets translated into ‘forms of life’. Because signs, forms, same thing, right? Splendid.

Although, isn't Curiosity's finding here equivalent of the VIking gas spectrometer returning a positive result? I'm sure if Viking gave two positive, and one negative results, they would have reported it, rightfully, as ‘signs of life detected on Mars’. So maybe not so out there.
 
YellowSubmarine said:
OK, local fake news here are already reporting that life was found on Mars. ‘Organic matter’ gets replaced with ‘signs of life’ (which is already a stretch), then that gets translated into ‘forms of life’. Because signs, forms, same thing, right? Splendid.

Although, isn't Curiosity's finding here equivalent of the VIking gas spectrometer returning a positive result? I'm sure if Viking gave two positive, and one negative results, they would have reported it, rightfully, as ‘signs of life detected on Mars’. So maybe not so out there.
Click to expand...
I believe it was the labelled release experiment on Viking that gave a positive result. The gas chromatograph and gas exchange experiments gave negative results. I'm not sure what was the result of the pyrolytic release experiment.
 
Asbo Zaprudder said:
^That's why more current technology is required or a sample-return mission or direct on-site investgation by a manned lab. However, we might well contaminate or destroy any fragile ecosystem if man finally makes it to the Martian surface. Do we care if we see Mars as a potential lifeboat for human DNA?

The BBC news site has a more detailed article about the latest findings:

Curiosity rover sees seasonal Mars methane swing - http://www.bbc.co.uk/news/science-environment-44405658
Click to expand...
That raises more issues.

If there are signs of life, should we allow samples back to Earth ? Contamination of the samples and contamination of our ecosystem aren't small considerations.

Would life from elsewhere pose a threat ? Would it have DNA, recognise (on a biological level) us as life and be able to interact with or infect us ?
 
Relayer1 said:
That raises more issues.

If there are signs of life, should we allow samples back to Earth ? Contamination of the samples and contamination of our ecosystem aren't small considerations.

Would life from elsewhere pose a threat ? Would it have DNA, recognise (on a biological level) us as life and be able to interact with or infect us ?
Click to expand...
Rocks from Mars and other bodies, blasted into space by meteor and asteroid impacts, are landing all the time on Earth. Take precautions, sure, but sample return to an orbiting lab would be prudent.

Maybe life got started elsewhere and seeded here. Perhaps DNA and RNA as found on Earth are ubiquitous and code for proteins using the same levorotatory amino acids and start and stop codons.

We just don't know.
 
Asbo Zaprudder said:
Rocks from Mars and other bodies, blasted into space by meteor and asteroid impacts, are landing all the time on Earth. Take precautions, sure, but sample return to an orbiting lab would be prudent.
Click to expand...
From the perspective of safety, a lab on the Moon would be even better, since that would be down in its own gravity well. Less chance of an accidental crash into Earth if things go sour, as has happened in various... movies.

Actually, orbiting the Moon should be good enough.
 
Asbo Zaprudder said:
I believe it was the labelled release experiment on Viking that gave a positive result. The gas chromatograph and gas exchange experiments gave negative results.
Click to expand...
Yes, yes.

My point is that the gas experiments gave a negative because of the perchlorate detected by Phoenix, however the Curiosity results are the equivalent of the Viking gas experiments hypothetically giving a positive.

In other words, Viking detected signs of life (as in biological activity, or some chemical process turning nutrients into CO₂), but no organic matter, which doesn't make any sense, so they discarded the LR results as false positives. Then the perchlorate from Phoenix puts the organic matter findings under question, and now Curiosity finds organic matter. As the gas experiments should have, but didn't.

However, I haven't read enough about Curiosity's finding yet to tell if that's a reasonable interpretation of things. :)
 
YellowSubmarine said:
Yes, yes.

My point is that the gas experiments gave a negative because of the perchlorate detected by Phoenix, however the Curiosity results are the equivalent of the Viking gas experiments hypothetically giving a positive. Like a substitute for it.

In other words, Viking detected signs of life (as in biological activity, or some chemical process turning nutrients into CO₂), but no organic matter, which doesn't make any sense, so they discarded the LR results as false positives. Then the perchlorate from Phoenix puts the organic matter findings under question, and now Curiosity finds organic matter. As the gas experiments should have, but didn't.

However, I haven't read enough about Curiosity's finding yet to tell if that's a reasonable interpretation of things. :)
Click to expand...
Sounds correct - I understand the ESA ExoMars rover has been designed to drill deeper and test for organics in rock that hasn't been blasted by UV for millennia. However, I don't think a range of experiments specifically testing for indications of lifeform activity is planned for any future mission. The legacy of the interpretation of the Viking results apparently lives on.
 
Last edited:
Methane is often times created by the Archaea microbes.

Archaea require neither sunlight nor photosynthesis. The microbe absorbs CO2, N2, H2S and gives off methane gas a waste product.

The atmosphere of Mars is 96% CO2 and 1.9% N2. There is obviously enough CO2 and N2 to provide the Archaea microbe with the food it needs.

If Hydrogen Sulfide is present on Mars then you can be guaranteed that Archaea microbes are present in the methane gas pockets approximately 12,000 feet below the Martian surface.

https://en.wikipedia.org/wiki/Composition_of_Mars
 
I remember reading an unscientific poll of scientists, where two thirds of the respondents were convinced Mars had life once, and one third were convinced Mars had life now. My reaction to it was “What are you all smoking?” – referring to the second lot who thought there could be life now. Ancient life on Mars was obviously a genuine possibility, but current life? No way. Now, adding the Viking, Phoenix and new findings together, I feel like, OK, fine. Those one third weren't high, in fact, maybe one third is close to the chances there is indeed life, according to my unscientific gut.

In hindsight, the whole big distinction between ancient and current life was foolish. It is true, Mars losing its atmosphere, surface water and turning into a seemingly barren rock would have killed any complex life; probably before it had even had the time to evolve, given that it happened a few billion years ago – by comparison, some basic multicellular life existed on Earth 3 billion years ago, but eukaryotes appeared only 2 Ga ago, and plants and animals are much much more recent than that, measuring in millions¹ of years. Mars didn't have a chance on that front.

However, it's very likely – probably more likely than not – that simple lifeforms would have survived and would live on in the current barren landscape. It's not just extremophiles on Earth that suggest that. Simple lifeforms, much less constrained due to the lack of complex inter-connected biology or small numbers, evolve really fast. Their simple RNA lacks the protective mechanisms that subdue rapid mutations, so they evolve really really fast. And the atmosphere and oceans weren't lost in a day, so the bacteria that potentially lived there had a whole eternity to adapt. I'm saying that if they were there, they did adapt. If Mars had life once – which would be the incredible thing here – chances are it still has lingering remnants of it.

I'm unsure if there was life on Mars once, so close to Earth – the implication of such thing would be potentially huge, as it could totally change what we expect to find out there in space (especially if we determine positively it's not related to Earth's life). I'm still leanings towards no. I just think there shouldn't be that much of a difference between now and then – life surviving once it evolved is way easier than evolving in the first place.

¹ Somewhat depressing. Complex life evolving within a billion years of the surface becoming uninhabitable, and a civilisation appearing only within 300 million years of the surface becoming uninhabitable – that doesn't speak well for the chances of other civilisations in the universe. It would be totally consistent with us being one of few to evolve fast enough to get something going before the planet is dead.
 
Last edited:
In my view, life on Mars was never a real possibility. Mars is too small for plate tectonics, as we all know, so there's no regeneration of resources at the surface. All of these supposed "potential signs of life" are just NASA yanking the public's chain to generate interest. Martian methane most likely comes from its chemistry -- olivine rocks, specifically, of which it has in plenty. These scientists know that, but ... "oh! We have to really get more expensive hardware out there to be absolutely, 100% sure that it's not LIFE!!!" Mars is not, and probably never was conducive towards life. It was wet for a time, even Viking proved that. But it was not for a very long time, though it was a very, very long time ago. I'm disappointed in NASA's always pulling this stunt, but their budget's always getting squeezed the hardest of any government agency and it's not fair. But duping the public isn't very scientific ... in fact it's pretty damn low.
 
You must log in or register to reply here.
If you are not already a member then please register an account and join in the discussion!

Sign up / Register


Back
Top