# Life on earth spread around the solar system



## Brian G Turner (Dec 12, 2013)

Interesting reading:
BBC News - Dinosaur asteroid 'sent life to Mars'

The really interesting point to me is about how they calculated that some of these rocks, potentially bearing the blueprint for life, would have left the solar system.


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## Alexa (Dec 17, 2013)

What ? Little terrestrial already on Mars when I still dream to see an ET myself ? 

Besides volcanoes, what kind of impacts could eject from Earth debris into the space ? I'm not an expert, but I doubt we could have some live inside a volcanic lava.

I would like to know what understands the expert by *very significant* in the new findings. Theory, theory ...


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## Brian G Turner (Dec 17, 2013)

The theory is that if something strikes earth, debris is raised up. And that very powerful (and rare) impacts will have enough energy to throw chunks of rock into space - rocks that could be big enough to hold colonies of bacteria, which are already proven to be very able to survive the harshness of space.


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## Alexa (Dec 17, 2013)

By this theory we should receive ourselves a huge rock or meteor from outer space and send them in return our own sample. We were hit in the past by meteorites, so this is plausible. We also know that kind of impact created huge craters. Could this impact raise up a rock from Earth ? I suppose a small one, will lend back after a while. For a huge one, the rock or meteor should hit a mountain maybe ? 

I'm usually very open to any theory that may help find us life on other planets, but I don't know why Brian, I don't believe in this theory. It has a very thick chance to be real. 

Why not explore the theory with a bacteria sent with one of our rocket launches instead ? Do you know that we already have a few rich eccentrics ready to go and live on Mars ? I hope I will live long enough to see that happens !


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## Stephen Palmer (Dec 17, 2013)

There are plenty of bits of Mars that have landed here on Earth after impacts.


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## Alexa (Dec 17, 2013)

Do you remember the article you've read about it ? I would like to read it.


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## Stephen Palmer (Dec 18, 2013)

Here's one, googled at random.

120 as of this year, including the notorious one with the "fossil bacterium".


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## paranoid marvin (Dec 18, 2013)

The chances of dinosaurs coming from Mars are a million to one.


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## ralphkern (Dec 19, 2013)

The name of this theory is Panspermia and has been subject to some experimental work.

The three obvious problems are:

1. Lifting the biomatter from the surface. (volcano or asteroid strike)
2. Survival of the DNA (if not the life itself) in space
3. Rentry (or entry if they're landing somewhere else)

None of those problems were found to be intractable, ironically the hardest was number 2, which seems counter intuitive compared to the conditions of 1 and 2. (Big explosions and high temperatures). Apparently experimental data shows that spores can survive for up to 6 years in space as long as they have some kind of shielding from cosmic radiation sources. 

Of course there may be other mechanisms at work which can extend that lifespan, making interplanatary and perhaps even interstellar transport possible. 

It is an exciting thought though


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## Mirannan (Dec 19, 2013)

Living organisms can live in rocks for quite a while; one unexpected place to find lifeforms was three kilometres down in an oil formation. (They were found in rock samples brought up by exploration drilling, and they were obviously very different from surface organisms.) Such life is very slow-metabolising. Given that, a big chunk of rock blasted away from the surface of a planet by a meteor strike might well have living things in it.

There is another theory about the formation of life on Earth that is quite interesting; that the first place for life to start in the Solar System was in fact Mars. The reason is that surface conditions there became suitable for life earlier than on Earth because Mars is smaller and therefore cooled faster.

So maybe we are all Martians?


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## Liz Bent (Jan 20, 2014)

If life is found on Mars that is sufficiently similar to life on Earth (that is, contains DNA), it might be possible to sequence the DNA and estimate how long ago the Martian cells diverged from Earthly cells. This would be absolutely fascinating, and if I recall right, it is one of the holy grails of astrobiology (actual life from another planet).

If life is found on Mars that is very unlike life on Earth (no DNA), that would also be fascinating, and be a strike against the theory of panspermia.


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