Signs of Life on Ancient Mars?

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Michael Watson

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Message 2038519 - Posted: 17 Mar 2020, 17:35:47 UTC
Last modified: 17 Mar 2020, 17:59:20 UTC

With all the attention being paid to the 'hibernation' of public participation in SETI@Home BOINC, some other interesting stories seem to have slipped by unnoticed.
Take, for example, the recent announcement about the discovery on Mars of organic compounds called thiophenes. The scientists responsible for this discovery aver that the likeliest explanation for their presence is life that existed anciently on Mars.

This is, of course, not proof that Mars once held life, or might even still do so, but it is a valuable clue that it may have, and will bear much further scientific attention.

An article with further details is linked below:
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Profile tullio
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Message 2038527 - Posted: 17 Mar 2020, 18:01:11 UTC
Last modified: 17 Mar 2020, 18:20:47 UTC

NASA should launch the Perseverance Rover misssion to Mars in July. The ESA-Roscosmos mission is delayed by two years. The Chinese orbiter-lander-rover mission Huoxing to Mars should launch in July but it seems that a Long March rocket launch has just failed, with no explanation given. Also the United Arab Emirates are sending a Probe to Mars.
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Profile Bob DeWoody

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Message 2038831 - Posted: 19 Mar 2020, 1:39:08 UTC

My guess is that I would bet the bank on finding irrefutable evidence of past life on Mars and a 50/50 chance of there being some form of life there now.
Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.
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Kerick Robery Leite de Sousa
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Message 2039740 - Posted: 22 Mar 2020, 19:13:17 UTC - in response to Message 2038519.  
Last modified: 22 Mar 2020, 19:16:19 UTC

It's quite a unfortunate coincidence, but the hibernation of seti@home was announced just a few days after one of my favorite scientists (and I guess also of many people here), the physicist and mathematician Freeman Dyson, has passed away. Dyson was not only a competent theoretical physicist, he was unafraid to let his imagination loose on a problem and push the theory in unexpected directions, sometimes even in controversial territory. The concept of the Dyson sphere is named after him.

Among Dyson many interests was the origins of life, writing a book on the subject, where he raises the hypothesis of independent origins for metabolism and replication, that afterwards merged into life as we know it. He also reasoned about SETI, formulating a alternative approach known as Dysonian SETI, where instead of concentrating in radio searches, you try to extrapolate the impacts of life and intelligence on its local environment to the limits of what physics allow, even if it seems very improbable, and from there you focus on what should be observed.

As the news of his death spread, Astechnica published an article where they mention a series of talks to celebrate his career, by occasion of his 90th birthday, in 2013. There's a very interesting talk by Joseph Kirschvink on the possibility that life actually originated in Mars, and from there colonized Earth afterwards, by means of rocks ejected by asteroid/comet impacts in Mars shallower gravitational well. Very underrated too, only ~300 views on youtube now. If I had to bet on it, I'd bet this hypothesis will eventually be proven true, when we get some samples to test it.

Beyond all evidence pointing to Mars being a environment more conductive to life when Earth had either a completely molten surface or a global ocean, for me It seems more in line with how life works. You start your life in a womb, but you can't live in a womb forever. The same way, there's no reason to believe the optimum environment for life to arise being also optimum to keep pushing it forward for billions of years. Migrations and relocations along the lifecycle of a species are ubiquitous in the biosphere. It also makes easier to explain the Fermi paradox. It's no longer necessary to assume Earth being rare. It's possible for Earth-like "pusher" planets and Mars-like "initiator" planets being both common, but a suitable pairing of them in any given star system being rare. Also its quite cool to think we all may be distant descendants of some martian archaea-like microorganism (an Archaeanaut?) lucky enough to survive a giant impact nearby, and months or years later the reentry in its stony, boulder-size "spaceship", for its descendants to colonize Earth, thriving long after Mars withered to its current state. Amidst the current pandemic, I hope to survive, and live long enough afterwards to see people set foot on Mars, what we may discover be the conclusion of a 4 billion year roundtrip, the longest ever, from Mars to Earth and back.

If you like the talk, there's some interesting papers on the subject here and here.
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Michael Watson

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Message 2040035 - Posted: 24 Mar 2020, 4:13:34 UTC
Last modified: 24 Mar 2020, 4:14:52 UTC

Thank you for that information, Kerick. Yes, its been realized for some time that Mars, being smaller in mass than the Earth, likely cooled sooner. Everything else being equal, this would have enabled life to establish itself there first.

Since its now understood that Mars once had oceans and a more substantial atmosphere, the possibility of this earlier development of life there is validated. And yes, Mars' lesser gravity would enable more meteorite impact debris to travel from there to Earth, than in the other direction. With all, it seems entirely possible that our microbial ancestors were colonists from the Red Planet!

It may someday be possible to confirm or refute this possibility. If life, or traces of past life are found on Mars, it may be possible to gauge its genetic similarity to our own. It may also be possible to assign a date to this life, based on its geological context. If this is older than that of the earliest known life on Earth, the possibility of the Martian origin of Earthly life would be strengthened.
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Message boards : SETI@home Science : Signs of Life on Ancient Mars?

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