Talk:Life on Mars/Archive 4

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Archive 4

meteorite section

Hi. What about the https://en.wikipedia.org/wiki/Tissint_meteorite ? There were some articles that claimed organic substances have been found inside, that were washed there while being under water, like https://actu.epfl.ch/news/traces-of-possible-martian-biological-activity-ins/ ... 93.198.202.34 (talk) 20:51, 8 January 2018 (UTC)

Hello. First, there is a difference between organic compounds (abiotic carbon- nitrogen-containing chemicals) and organic matter (biological). The meteorites mentioned in this article are thought to host some tiny shapes that could be interpreted by some, as micro-fossils, and although they may contain carbon, nitrogen sulfur, oxygen (organic compounds) none show biological matter (remnant of cells). Many meteorites have been found that contain organic compounds (carbon, nitrogen, oxygen, sulfur) but they are abiotic, meaning naturally occurring chemicals not metabolized by life forms. No single compound will prove life once existed. Rather, it will be distinctive patterns present in any organic compounds showing a process of selection. For example, membrane lipids left behind by degraded cells will be concentrated, have a limited size range, and comprise an even number of carbons. Similarly, life only uses left-handed amino acids. I hope this clears that up. In fact, organic compounds are abundant in cosmic dust, comets, asteroids and meteorites, they are the most abundant atoms in the universe, but none of those objects analysed in situ has shown the peculiarities of being handled (metabolized) by life forms. I hope this helps. Cheers, BatteryIncluded (talk) 22:32, 8 January 2018 (UTC)

I just saw your link to https://actu.epfl.ch/news/traces-of-possible-martian-biological-activity-ins/ It is dated 2014 and it made no waves in the astrobiology journals. I'll take another look at it and research the literature. Cheers, BatteryIncluded (talk) 22:51, 8 January 2018 (UTC)

Yes, it sounded promising by the time, the NHM meteorite curator in Londen called it the most important meteorite of the last 100 years, maybe only because they paid so much money for it. There was talk of organic substances similar to precursors of fossil oil, that had been in the water and washed into the crack, if I remember it correctly. What became of all that? Looking forward to learn it, anyway thanks for the explanations! 93.198.202.34 (talk) 05:00, 9 January 2018 (UTC)

Nothing new here? What did the research find? 93.198.217.89 (talk) 19:26, 20 February 2018 (UTC)

Hello! The meteorite is very valuable because it was retrieved soon after its fall so it is considered "uncontaminated" or non-weathered by Earth. It also has a geological origin different from any other Mars meteorite found so far. However, it seems to be the most shocked Mars meteorite found to date (see: Meteorite shock stage) meaning that the impact was large enough to excavate the material from several km deep, and the high pressure and the released energy of the impact were so high it transformed the material drastically - at molecular level. Although there is carbon within, any biological matter would not have endured the heat and pressure. The carbon isotopic ratios do not suggest biological alteration or selection. Regarding morphology (looking for microfossils) the same applies: the pressure and impact were so high, the material melted completely, affecting its molecular chemistry (creating some different compounds) and then crystalized. No organic matter (biological or living matter) could have remained after these extreme alterations. It seems one team suspects the impact site on Mars included hydrothermal vents, that means water and organic compounds (abiotic), but after the shock, pressure, melt and crystallization, there are no clues that may suggest biotic matter or biological chemistry. Life can't be ruled out, but one would have to make a giant leap of faith (unsupported by science) to say the carbon present was previously incorporated into living matter just before the impact. Overall, it seems a recent, uncontaminated find of great value, but it does not suggest chemical or morphological clues to life on Mars.BatteryIncluded (talk) 00:58, 21 February 2018 (UTC)

Thank you, that was a nice update. So the scientists were too enthusiastic with their first claims about a possible biological origin of the carbon in Tissint, yet it can not be proven scientifically, but also is still possible and can also not be excluded scientifically, one just doesn't know and cannot tell anymore from the impact-modified material. Interesting! Leaves the question open. If the impact was strong enough to exvacate material from deep inside the crust, it would also have destroyed all existing life in the near area, I guess. I also wonder how long relics and traces, fossils, would exist on Mars. Are we talking about millions or even rather billions of years (due to no tectonic plate-movement like on earth)? Or are there also other natural processes that slowly destroy such traces, like the UV-radiation at the surface? I wonder if there could have been life on Mars a long time ago und we just cannot tell anymore, because no traces left. We would never know, then? Looking forward to what the ESA Trace Gas Orbiter will find... 93.198.217.89 (talk) 13:28, 21 February 2018 (UTC)

Earth life based from Mars?

Old article but some people think a certain bacteria with high levels of radiation-threshold could be from Mars, deposited here via panspermia. Also on the flipside, bacteria could have picked up and hitchiked on the Rovers.137.118.103.153 (talk) 19:57, 24 February 2019 (UTC)

You cite no sources, but Deinococcus radiodurans dies under Mars-like conditions (radiation, low pressure, low temp, no oxygen). So suspecting it to be Martian is a stretch that needs evidence in order to even begin to formulate such hypothesis. Rowan Forest (talk) 00:25, 25 February 2019 (UTC)

Fungi found on mars

check out this paper Evidence of Life on Mars? http://journalofastrobiology.com/Mars5.html

newest pictures and analysis point to actual life on mars in form of fungi and/or lichen

maybe this should be added to the wiki-article — Preceding unsigned comment added by 87.147.208.248 (talk) 10:05, 17 April 2019 (UTC)

No, fungi was not found on Mars. The Journal of Astrobiology and Space Science Reviews is a new journal of unknown reliability, and on its inaugural first edition Rhawn Joseph —known for his conspiracy stories— makes yet another accusation of coverup by NASA and as "proof" he usually presents pictures of rounded rocks, and as "supporting evidence" he quotes resistance of some extremophiles to simulated Mars surface conditions. Some years ago he actually filed a lawsuit against NASA claiming a systematic coverup of extraterrestrial life. [1] In one word: WP:FRINGE. Rowan Forest (talk) 13:50, 17 April 2019 (UTC)

Frankly, I don't see the difference between examining photographic images of possible fungi on the surface of Mars and examining photographic images of possible bacteria in meteorites, which is already presented in the article as potential evidence for life on Mars. Nobody is saying that we should update the article to say "yes! We've found life on Mars!", but Joseph's claims have sufficient evidence to merit academic discussion, and that discussion should be accurately represented in this article as it develops. Nodrokov (talk) 16:49, 9 May 2021 (UTC)

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