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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

#171

Post by chadzawistowski »

peter303 wrote: post #142

Solar system life may turn turn out t chemically similar. That is because it arose on one body, then cross-infected other other bodies by meteorite transfer over many millions of years. Mars became geologically stable before Earth, so it could have been the earliest place for life. Then Martian meteors infected Earth.

How could a meteor have launched from Mars and reached Earth? It stretches my mind to imagine a situation where a meteor drops down, picks up life, then drops it off on the next planet. Are there records of meteoric impacts like that?

The best situation I can think of is a catastrophic volcanic explosion which launches a chunk of the planet into space, but that still sounds far-fetched to me.

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

#172

Post by cLeEOGPw »

chadzawistowski wrote: post #171
peter303 wrote: post #142

Solar system life may turn turn out t chemically similar. That is because it arose on one body, then cross-infected other other bodies by meteorite transfer over many millions of years. Mars became geologically stable before Earth, so it could have been the earliest place for life. Then Martian meteors infected Earth.

How could a meteor have launched from Mars and reached Earth? It stretches my mind to imagine a situation where a meteor drops down, picks up life, then drops it off on the next planet. Are there records of meteoric impacts like that? The best situation I can think of is a catastrophic volcanic explosion which launches a chunk of the planet into space, but that still sounds far-fetched to me.

Here's (https://en.wikipedia.org/wiki/Martian_meteorite) an example how. Asteroid impact.

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

#174

Post by mangeletti »

foota wrote: post #173

Does anyone else think that the form of life found on Mars would most likely be completely distinct from what is found here, down to the molecular and cell level?

Other than the possibility that the origins of life and potential life on Mars are the same, I think the same thing as you.

Imagine it is completely distinct, and doesn't have cells.

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

#175

Post by cLeEOGPw »

VLM wrote: post #70
eddd wrote: post #52

Earlier quoted context omitted.

Actually I found comprehensive answer here if anyone is interested: http://www.space.com/13639-alien-life-methane-habitable-zone...

It doesn't really say "why". Water ionizes really conveniently so you can make it an acid OR a base (which is sorta unusual and it can talk to acidic or basic things), and is polar (its got a + and a - electrical side, more or less, so it can talk to + or - things), and has hydrogen bonds (so you get liquid lifestyle at gas temps) For one why, look up amphoteric and zwitterion. Water has a super convenient pH range w…

Sometimes I wonder that not only it is not possible for other forms of life to exist that wouldn't use water, carbon and others, but that we have life just because it so happened coincidentally that our universe were created with the exact properties needed for the laws of physics to support life for a short while in some places.

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

#176

Post by foota »

mangeletti wrote: post #174
foota wrote: post #173

Does anyone else think that the form of life found on Mars would most likely be completely distinct from what is found here, down to the molecular and cell level?

Other than the possibility that the origins of life and potential life on Mars are the same, I think the same thing as you. Imagine it is completely distinct, and doesn't have cells.

Yeah, I missed that caveat. I'm really excited to see what it might be and how it could potentially change our definition of what's living.

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

#177

Post by dang »

InclinedPlane wrote: post #157
crusso wrote: post #143

Earlier quoted context omitted.

Please don't invent hostile motives in my post when none were being offered. I was simply pointing out the impasse expressed in the article. This isn't NASA's internal blog of scientists, so I'd think that possibly dumb speculation could be offered. The iteration explanation makes some sense, although these seem like very expensive iterations.

You are literally strolling into a subject you know nothing about and putting forward an opinion that amounts to "wow, these guys sure are dumb, huh?" It's a very common way to comment on science stories and it's absolutely infuriating. Why not this? "So, I don't understand what's going on here, this seems weird because of X, Y, or Z, can someone explain what's going on?" Or this? "Is NASA really so dumb that they wo…

You're piling on too hard here. It's unfair of you to put things that crusso didn't say in quotation marks. That is guaranteed to produce a defensive reaction that makes the argument worse rather than better. And then you depict a caricature so idiotic, it's surely unfair.

You're correct of course that commenters are too quick to make gotcha criticisms when they ought to pause and realize that there's almost certainly more going on. But this is something most people do, and we should each take care of our own part of it first.

There's another aspect of this too. On HN, the problem is as much created by the upvoters as by the commenter. Sometimes a comment was intended as an offhand observation—the sort of thing you'd throw out to friends, not meant to sound authoritative, let alone pompous. But by the time it gets upvoted to the top comment, it can sound like the criticism of an asshole. HN unfortunately has a number of areas like this, where every individual contribution is positive, or at least well-intended, yet the total they add up to is negative. Let's not make the mistake of blaming individuals for a collective problem that we all contribute to.

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

#178

Post by joesb »

WalterBright wrote: post #110
david_shaw wrote: post #87

Earlier quoted context omitted.

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?

At some point we'll either have to either stop worrying about life on Mars being hidden under a rock somewhere or forever put a "humans keep out" sign on Mars.

If there were life on Mars. It will be the our first, and may be the possible only, source of foreign life to study.

I don't think we want to contaminate or destroy our only source of knowledge on other kind of life.

May be we can do that later, once we study them enough or have kept it enough for further study. But let's not make our first decision be "We gonna destroy it someday anyway, let's just stomp on it carelessly right now"

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

#179

Post by Houshalter »

bglazer wrote: post #158
Havoc wrote: post #153

Earlier quoted context omitted.

What is the real contamination risk though? Suppose some biological particle makes it to mars. Then we pick it up, discover that its very dead already, DNA sequence it and find that it matches the common flu. Write it off as contamination, rinse & repeat until we find something that is alive & looks like green men. Or can science genuinely not distinguish earth contaminants vs alien life?

One possibility, perhaps very unlikely and perhaps somewhat likely, is that Earth life could actually survive and adapt to Martian conditions and subsequently destroy existing Martian life. That seems almost comically improbable, but given that we've found that lichen can survive in the vacuum of space for a year and a half [1] and the mere existence of life on hydrothermal vents and inside Chernobyl[2], I think we c…

If there is life on mars, then it would be highly adapted for the Martian Climate over millions of years. It's unlikely that Earth Life would be able to out-compete them.
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