On: Signs of Liquid Water Found on Surface of Mars, St...

[a3n]

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.

[tempVariable → a3n]

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

[icoder → tempVariable]

I think your parent post was talking about that we may have taken earth-life to Mars (not vice versa)

[a3n → icoder]

Correct.

But there are Mars rocks that have been busted loose from Mars, and orbited down to Earth.

https://en.wikipedia.org/wiki/Martian_meteorite

[jkaunisv1 → tempVariable]

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

[gaius → jkaunisv1]

Well, yes and no. There is the Sabatier process:

https://en.wikipedia.org/wiki/Sabatier_reaction#Manufacturin...

[wtracy → jkaunisv1]

We don't need to: https://en.wikipedia.org/wiki/Sabatier_reaction#Manufacturin...

[jkaunisv1 → wtracy]

You're right! Even though I cited the Sabatier reaction to a coworker today when discussing the news, I didn't really think about it when answering. Also, for some reason I thought it wasn't yet a technical reality.

I guess also wrapped into my statement was the thought that to be able to launch something back it would have to be landed very well and require some very complex machinery to prepare for launch, given the success rates of just being able to land something on Mars without it breaking. I went with the first reason off the top of my head :)

[outworlder → jkaunisv1]

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).

[jkaunisv1 → outworlder]

Oh, I wasn't discounting the future possibility - there's definitely nothing impossible about it, and in fact I agree it's quite doable. Just that we don't have it yet.

[Florin_Andrei → a3n]

> 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.

[a3n → Florin_Andrei]

There's strong speculation that there was an ocean on Mars, many years ago. Possibly mild enough to get started.

[Florin_Andrei → a3n]

> There's strong speculation that there was an ocean on Mars, many years ago.

Yep. Here's a great book on the topic:

http://www.amazon.com/Travelers-Guide-Mars-William-Hartmann/...

[hugh4 → a3n]

We simply don't know how likely life is to arise given the right chemical conditions. We also don't know what those conditions are.

It may still be that life is so unlikely that it only happens on one out if every billion planets where the right conditions exist.