Scientists get closer to solving chemical puzzle of the origin of life - synthesis of pantetheine

[Ophiolite]

Much like you, I'd like to think that there was life on Mars. However, I haven't seen any evidence that there was. Until I have access to evidence that there was, or maybe still is, I will continue to conclude that there isn't. If you can provide compelling evidence that the Viking Lander discovered Martian life, I'd like to see it.

This is a peculiar reaction to my post where I stated "I . . suspect that the Viking Lander experiments did discover Martian life. (Not conspiracy theory - just a more cautious approach to the data.)" The key words here were "suspect" and "more cautious approach to the data". Why then, given those caveats, would you ask for "compelling evidence"? If I had compelling evidence I wouldn't just "suspect", nor would I need to be "more cautious in interpreting the data".

You have access to the evidence ; NASA had access to the evidence; the world had access to the evidence. Two of the three experiments on the Viking Landers produced results that, prior to the landings, would have been taken to indicate/strongly suggest the presence of life. This was on both landers, separated by half a planet. Because the mass spectrometer (whose sensitivity has been questioned) showed no organics NASA and its research teams came up with an alternate explanation.
That was a reasonable interim solution. What was not reasonable was then taking that as a final conclusion and failing to devise more sensitive experiments for follow up missions. Instead we are left "looking for the water". Why? We know Mars was replete with water, perhaps not Earth standard, but seas and lakes and rain and snow.

I gave up following this lost argument a decade ago, but if you wish I'll dig out some references fo you.

And, by the way, I don't "like to think there was life on Mars", I just wish ambiguous evidence to be treated intelligently and investigated properly.

I feel similarly about the idea that all possible reactions have necessarily already occurred here on Earth. It can be considered one data point.

If you read carefully the conditions under which I think it probable that possible reactions will occur during the course of many millions of years you will see that those conditions implicitly convert the possible to probable. Which is why I said that I thought there was some crossed wires in what was meant by possible. (Or words to that effect.)

 

[SelfSim]

... What was not reasonable was then taking that as a final conclusion and failing to devise more sensitive experiments for follow up missions. Instead we are left "looking for the water". Why?

Well, by looking for evidence of past water flows, they then found organic chemicals.

And, by the way, I don't "like to think there was life on Mars", I just wish ambiguous evidence to be treated intelligently and investigated properly.

Fair enough.
They're using 'SHERLOC' on board of the 2020 Perseverance rover, which is a UV Raman scattering spectrometer designed to detect organics (and it has done so recently I believe). That seems to be a fairly intelligent level-headed approach to continuing investigations, no(?)

 

[Ophiolite]

Well, by looking for evidence of past water flows, they then found organic chemicals.

True, but almost half a century after the Viking results. In interpreting a suite of experiments designed to detect the presence of life NASA chose to reject completely the possibility that the postive results from those experiments were genuine. Now, I acknowledge that the results - on balance - probably have a non-biological explanation, but given the importance of the discovery the first follow up lander should have contained new experiments to thoroughly test the non-biological explanation and make a renewed attack on detecting possible life. Instead the "it's not life" viewpoint won the day with an absolute halt to the type of tests that are only now being carried out.

They're using 'SHERLOC' on board of the 2020 Perseverance rover, which is a UV Raman scattering spectrometer designed to detect organics (and it has done so recently I believe). That seems to be a fairly intelligent level-headed approach to continuing investigations, no(?)

It's not bad, but it is 45 years too late!

(As an aside, I was unimpressed by the hoopla surrounding ALH84001 from the outset. It was worth investigating and that investigation was properly conducted. The Viking data lacked an equivalent rigorous approach.)

 

[SelfSim]

True, but almost half a century after the Viking results. In interpreting a suite of experiments designed to detect the presence of life NASA chose to reject completely the possibility that the postive results from those experiments were genuine. Now, I acknowledge that the results - on balance - probably have a non-biological explanation, but given the importance of the discovery the first follow up lander should have contained new experiments to thoroughly test the non-biological explanation and make a renewed attack on detecting possible life. Instead the "it's not life" viewpoint won the day with an absolute halt to the type of tests that are only now being carried out.

It think the Viking experiments were a big learning experience for NASA. The lesson (I think) was that, without comprehensive geo-chemical details of the environment, any given sample isolated from that environment, doesn't have to carry the meaning we'd like to assign to it. So, the outcome of that, is more intensive testing of said environment .. which is exactly what we've seen over the intervening years since Viking.

The Viking life probes were also a very expensive, (even over-the-top?), mission for NASA at the time. The return of ambiguous results must have been judged by them (covertly) as a not-to-be-repeated failure, I guess(?)

It's not bad, but it is 45 years too late!

(As an aside, I was unimpressed by the hoopla surrounding ALH84001 from the outset. It was worth investigating and that investigation was properly conducted. The Viking data lacked an equivalent rigorous approach.)

The upcoming 'Rosalind Franklin' probe (2028?), previously known as the 'ExoMars rover', will also include extensive morphological and chemical subsurface 'life-signature' investigative techologies (ie: the 'Pasteur' payload), perhaps, now that there is an extensive detailed catalogue of the surface geo-chemistry, or more simply, because it is being developed/funded by ESA .. and not solely by NASA(?)