Life on Earth, courtesy of Mars?


#1

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#2

Is there life on Maaaaaaaaaaaaars...


#3

#4

There was a brief period when the theaters I normally go to had vending machines selling soundtrack CDs of the movies that were playing. If they'd had one when I saw The Life Aquatic... it would have been the first, and possibly only, time that I actually used one. Fortunately there was a nearby record store that served my needs.


#5

As much as I'd like this to be true (or at least I'd like there to be enough information that it could be accepted as not only plausible but highly likely) it raises at least as many questions as it potentially answers. The question of how life originated will still be an open one. The locus will merely have moved slightly.


#7

It seems the idea is that one model for life's origin is more likely to have happened on Mars than Earth. Of course for that to have any real weight, it would have to be more likely to have happened there and transferred here, than for the same process or any other to have created life directly on Earth. Which like most panspermia ideas is all but a non-starter; but to be fair, all I have to go on is the popular report, not Benner's argument itself.


#8

In that case maybe it's our duty to put it back.


#9

Acck! Acckk Acckk!


#10

If true certainly raises an interesting wrinkle to finding life elsewhere in the universe. What if finding one planet with the proper conditions isn't enough? What if life always requires several planets - one where the building blocks can be put together, and another where life can actually thrive once that happens? It would mean life is a hell of lot less likely to occur, even with "Earth-like" planets being common.


#11


Quatermass called it first.


#12

In a universe of infinite worlds, it would only be infinitely less likely.


#13

I am so sick an tired of hearing about this theory. Every few years someone dusts-off this moldy tidbit.


#14

Dammit. Slim Whitman died this year, just when we really, really needed him.


#15

The problem I see with "requires several planets" is what if one planet just happens to have all that's needed? Or if that planet changes at just the right time to support both phases. I'm not necessarily shooting your idea down, just showing the alternative.


#16

Not that I'm an expert, but why is the transference such an unlikely concept? We have Martian meteorites here (possibly - but not likely - with fossilized microbes). We have microbes that are capable of surviving a long journey from Mars (we've found Earth microbes that have survived 553 days in space). If microbes just happen to end up in well-protected crevices in meteorites, they could possibly survive the fiery entry through the atmosphere.

I'm not arguing for or against panspermia, just saying it's not as unlikely as it may seem (coming from a non-expert like me).


#17

Or we could kill it an eat it. Unless it's meat, then I have to bow out.


#18

My command of English sucks today...


#19

There's a motion to make Mars the reference of our future. It's not. Grant money will not be allocated to fringe ideas.


#20

I'm not saying it's impossible, but you're describing long odds. And it's not enough for a rock to get blasted from Mars to Earth that happens to have microbes deep enough to survive the journey, they have to be able to survive the new habitat.

Consider: they'll almost certainly face different temperature and salinity, things that already stop many microbes from growing even if they endure them. The article's point was that Mars had different chemistry, but for panspermia to work they can't need a single ion concentration they won't find here. Any organics will be foreign and so potentially toxic, and it often takes much less toxin to kill something than food to sustain it.

From that alone, I suspect only autotrophs have much chance. And that probably means photosynthesis, because happening upon two chemicals you know how to extract energy from isn't likely; most chemotrophic bacteria today are really taking advantage of our plentiful oxygen. But sunlight is dangerous unless you can quench excess absorption and block harmful radiation, and now the sun has turned twice as bright, filtered through a different atmosphere.

Now, these chances may not be insurmountable over a few billion years - but that applies to every chance against forming life too. If we were talking about a place where new life was forming all the time, panspermia might be worth thinking about...but if we're comparing the problems with jumping worlds against something like not having as many of the deposits we think might have been important? I'd say the idea should be dead in the hot irradiated toxic water.


#21

"We are the Martians."

If terrestrial life did begin on Mars and was transported here ... where else might it have gone, and where else might it have taken root?