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Signs of Liquid Water Found on Surface of Mars, Study Says

nytimes.com

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Re: Signs of Liquid Water Found on Surface of Mars, Study Says

#81

Post by Florin_Andrei »

a3n wrote: post #26

If there is water of any sort on Mars, ice, liquid, salty, whatever, I think finding life on Mars is inevitable. Life is very, very persistent, and niches will be filled. Unfortunately it's also all but inevitable that we'll bring some with us, if we haven't already. Life is persistent, and ever-surprising.

> Life is very, very persistent, and niches will be filled.

But I think it's safe to assume it's quite fragile at the very beginning, and therefore conditions must be milder for it to appear at all.

Once it takes off it's probably much more sturdy.

Re: Signs of Liquid Water Found on Surface of Mars, Study Says

#82

Post by outworlder »

jkaunisv1 wrote: post #28
tempVariable wrote: post #27

Earlier quoted context omitted.

Interesting. I read that in Jeff Goldblum's voice as well. Were there any missions that lifted off Mars and came back to Earth ?

No, we don't have the capability to land something on Mars with enough fuel for it to take off again.

Its a hard engineering problem, yes - but not that far-fetched. It's an even harder political problem, though.

It's hard to justify the required R&D expenses without appealing to emotion (such as sending humans).

Re: Signs of Liquid Water Found on Surface of Mars, Study Says

#83

Post by rm445 »

beambot wrote: post #79

They won't explore the water-flowing sites to: "minimize the chances of life inadvertently crossing the solar system." So let's just spread life intentionally. It seems like that is one of our goals anyway -- not necessarily for governments (ie. NASA), but certainly for private space flight.

The aim is to settle the question of whether life exists on Mars, or ever has, before clouding the issue with modern contamination. I say modern just in case of various panspermia-type possibilities.

That doesn't preclude eventually spreading life to Mars. Even if living indigenous bacteria, or even plant life(!) were found - I think this is the most ambitious scenario now conceivable, the 'Mars mat' of fiction suviving in caves - it likely wouldn't be an argument to stop colonisation, though it might have bearing on arguments about terraforming.

Re: Signs of Liquid Water Found on Surface of Mars, Study Says

#85

Post by NhanH »

leonardzen wrote: post #84

Wouldn't it be bad if life forms are found in Mars, according to this? http://waitbutwhy.com/2014/05/fermi-paradox.html

Speaking in Bayesian probability, it's bad if life forms found on Mars are more advanced than human, and good if it's much less advanced, or even very primitive (as it means the Great Filter might be at an earlier stage than us right now).

And it won't be the former case, for obvious reason.

Re: Signs of Liquid Water Found on Surface of Mars, Study Says

#86

Post by ethbro »

mapt wrote: post #62
sanoli wrote: post #50

Earlier quoted context omitted.

Isn't this nearly impossible in the long (although here I mean really, really long) term? Think of trying to minimize the chances of some flu strain in one continent from getting to the other. I mean, once humans start going here and there, what do you do, do you keep everything in containment (exhaled gases, excrements, every form of waste)?

The only way you could keep human biota 100% contained is if the humans never interacted with anything outside the welded-shut steel sphere they inhabited - in which case, why bother bringing them to Mars?

The view across part of Valles Marineris?

Re: Signs of Liquid Water Found on Surface of Mars, Study Says

#87

Post by david_shaw »

Symmetry wrote: post #73
mapt wrote: post #44

Earlier quoted context omitted.

All equipment designed for landing on Mars in the modern era is extensively sterilized. The concern is that given what we've learned about microorganisms in space, this may not be enough; "Extensively sterilized" is never "Perfectly sterilized", at least, not without building it out of solid metal and annealing it in space. There was also a last-minute variance granted to the drill bit on Curiosity, which was contami…

There have certainly been metioroids starting on Mars that made it to Earth without being sterilized[1]. Now, Earth does have a deeper gravity well which might make a difference but Earth microbes have had geological epochs to make the trip to Mars wheres you'd only expect a meteoroid to remain recognizable on Earth's surface for that long in comparison. So I figure that if contamination of Mars by Earth life was a p…

That makes sense, but wouldn't it be reasonable to assume that there's a major difference between natural seeding of life on other planets via meteors, and humans bringing it over while trying to find natural life?

Furthermore, what if life on Mars were fragile enough that Earthly microscopic organisms destroyed it?

Re: Signs of Liquid Water Found on Surface of Mars, Study Says

#88

Post by thaumaturgy »

NhanH wrote: post #85
leonardzen wrote: post #84

Wouldn't it be bad if life forms are found in Mars, according to this? http://waitbutwhy.com/2014/05/fermi-paradox.html

Speaking in Bayesian probability, it's bad if life forms found on Mars are more advanced than human, and good if it's much less advanced, or even very primitive (as it means the Great Filter might be at an earlier stage than us right now). And it won't be the former case, for obvious reason.

Finding life on Mars would still change one of the polynomials of the Drake Equation, which would shift upward the overall expected probability for intelligent life in the cosmos, which is probably what leonardzen means.

But "we don't have enough data yet" still seems like a good answer to the Fermi Paradox anyway.

Re: Signs of Liquid Water Found on Surface of Mars, Study Says

#89

Post by zokier »

crusso wrote: post #12

R.S.L.s are treated as special regions that NASA’s current robotic explorers are barred from because the rovers were not thoroughly sterilized We're not going to sterilize our research equipment going to Mars and we're not going to search likely sites where we could find life because we don't want to contaminate them. And yet, looking for signs of life native to Mars (or even water which might support life) is the to…

> And yet, looking for signs of life native to Mars (or even water which might support life) is the top reason we're there, judging by the headlines. Seems like someone in NASA needs to work out this conflict. (emphasis mine)

maybe it is just media that needs to work out this conflict.

Re: Signs of Liquid Water Found on Surface of Mars, Study Says

#90

Post by mrec »

Symmetry wrote: post #73
mapt wrote: post #44

Earlier quoted context omitted.

All equipment designed for landing on Mars in the modern era is extensively sterilized. The concern is that given what we've learned about microorganisms in space, this may not be enough; "Extensively sterilized" is never "Perfectly sterilized", at least, not without building it out of solid metal and annealing it in space. There was also a last-minute variance granted to the drill bit on Curiosity, which was contami…

There have certainly been metioroids starting on Mars that made it to Earth without being sterilized[1]. Now, Earth does have a deeper gravity well which might make a difference but Earth microbes have had geological epochs to make the trip to Mars wheres you'd only expect a meteoroid to remain recognizable on Earth's surface for that long in comparison. So I figure that if contamination of Mars by Earth life was a p…

Well, calling Allan Hills 84001 "unsterilized" is a bit of a stretch, since even the most optimistic theory is that it contains fossilized lifeforms, not live ones.

I dunno. I agree that something like the K/T impactor probably blasted bits of our planet all over the Solar System, but I suspect the depth of the gravity well brings more factors into play than just "how long it would take for ejecta to get to X". For example, accelerating a bit of surface to escape velocity would involve a lot more energy on Earth than on Mars, and at the point of impact I'd have thought that energy would translate to possibly-sterilizing heat.

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