Earth Ejecta Could Seed Life On Europa 130
KentuckyFC writes "Various astronomers have studied how far rocks can travel through space after being ejected from Earth. Their conclusion is that it's relatively easy for bits of Earth to end up on the Moon or Venus, but very little would get to Mars because it would have to overcome gravity from both the Sun and the Earth. Now, the biggest ever simulation of Earth ejecta confirms this result — with a twist. The simulation shows that Jupiter is a much more likely destination than Mars. So bits of Earth could have ended up on Jovian satellites such as Europa. Astrobiologists estimate that Earth's hardiest organisms can survive up to 30,000 years in space, which means that if conditions are just right, Earth ejecta could seed life there."
Elements are not seeds (Score:5, Insightful)
the seeds of life are simply everywhere, inside and outside the solar system, and life is simply always lying dormant, everywhere in the galaxy
I'd say the elements of life are everywhere, but not the seeds. Having the material but not the proper information is not enough. Life is composed by amino acids, but those are merely the bricks used to make proteins. One must have a suitable floor plan to build a house.
What makes conditions on early earth so special is not the existence of organic chemistry, but the special circumstances, so far not known to us, that brought the formation of complex self-reproducing chains of amino acids.
Re:How about the opposite? (Score:4, Insightful)
I think an unspoken assumption you are making is that the evolution of life "advances" toward intelligence linearly at a common rate. This isn't really accurate. Advanced life does not necessarily mean intelligent life.
Life may well exist on Europa, and may well have existed for just as long as life on earth. We can look for examples in the communities surviving around deep ocean thermal vents (which are likely the best analog we have for the environment in Europa's oceans). Those environments are teaming with life in a fairly small area. That life isn't intelligent, and may never face the evolutionary pressures that will lead to the development of intelligence, but is very very highly adapted to an extremely harsh environment. That level of evolution can be considered every bit as "advanced" as our intelligence.
Re:Slight problem... (Score:4, Insightful)
Surely any event that could eject material from earth with sufficient energy to escape Earth's gravity well would tend to melt the ejecta at the same time,
No. Some, but not all. Here is a mechanism - impacting object hits, penetrates, and is stopped and imparts spherical shock wave into the Earth (or other planet) some depth inside the planet. (In simple terms, it explodes inside the crust of the Earth.) Some part of that shock wave is propagating near vertically up, away from the planet (including, maybe, parts that reflect from internal structure). These shocks lift material up out of what becomes the crater. For a 2 km crater (such as the Great Meteor Crater in Arizona), these shocks turn the layers in the near surface material upside down, just lifting and flipping them over in much the same way you would flip over a pancake, moves a mass of material maybe 1 km, without vaporizing any except for a small fraction near where the impactor stops. For a 100+ km crater, that some process pushes the some of the surface layers off the planet entirely (and also causes long rays, such as are found on the Moon). While some of the ejected material is vaporized, most isn't, and some is treated quite gently (for a massive explosion), gently enough that biological spores and the like could survive the experience.