Nasa had proven Mars once had water and still has under ground. So dose that mean mars once had life or maybe still has?

  • $\begingroup$ No, it doesn't mean anything other than that Mars had large amounts of flowing water billions of years ago, but that's not a physics question to begin with, but a general science and logic question. $\endgroup$ – CuriousOne Oct 28 '15 at 12:08
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    $\begingroup$ How can anyone answer this? It will be answered when some future Mars mission finds incontrovertible evidence of life, and not until then. $\endgroup$ – John Rennie Oct 28 '15 at 12:12
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    $\begingroup$ OK, seriously: existence of water is pretty much required for all Terran lifeforms, but 1) existence is not sufficient, just necessary, 2) there could well be life forms which are not water-based. $\endgroup$ – Carl Witthoft Oct 28 '15 at 12:12
  • $\begingroup$ What is your definition of life? $\endgroup$ – Qmechanic Oct 28 '15 at 12:13
  • $\begingroup$ @JohnRennie: You have answered it the only way that an honest scientist will answer these kinds of questions. Sadly that leaves a lot of folks at NASA outside of the "honest scientist" category these days. $\endgroup$ – CuriousOne Oct 28 '15 at 12:15

As yet unknown - there are some hints that life might exist ie methane emissions, but no proof.

  • $\begingroup$ The methane measurements seem rather shaky. As of now I wouldn't even bet a cup of Pete's Coffee on them. $\endgroup$ – CuriousOne Oct 28 '15 at 12:13
  • $\begingroup$ Why don't they just go to where water is flowing, scoop up some sub-surface mud and put it under a microscope? Is it really that difficult for the next Mars lander? $\endgroup$ – user56903 Oct 28 '15 at 12:16
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    $\begingroup$ I suspect for the same reason that one can probably grab a microscope, go to the Atacama, dig up a scoop of dirt and come away with the conclusion that this planet never had life... and with fossils one really has to hit the right layer or there is absolutely nothing. Honestly, if Mars once looked like the place where I grew up, they would have seen fossilized shells from ten feet away.. but they haven't... and that's not surprising. The easy to see stuff is maybe 500 million years old and by that time Mars was dry. $\endgroup$ – CuriousOne Oct 28 '15 at 12:24
  • $\begingroup$ @CuriousOne How about a cup of Peet's coffee? :-) $\endgroup$ – Carl Witthoft Oct 28 '15 at 14:09
  • $\begingroup$ @CarlWitthoft: I suspect that soon they could insert a microscope into my skull without finding a single neuron... :-) $\endgroup$ – CuriousOne Oct 28 '15 at 17:39

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