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Earth Space Science

Scientists Study Trajectories of Life-Bearing Earth Meteorites 199

Posted by samzenpus
from the we-come-from-earth dept.
Hugh Pickens writes "About 65 million years ago, Earth was struck by an asteroid some 10 km in diameter with a mass of well over a trillion tonnes that created megatsunamis, global wildfires ignited by giant clouds of superheated ash, and the mass extinction of land-based life on Earth. Now astrobiologists have begun to study a less well known consequence: the ejection of billions of tons of life-bearing rocks and water into space that has made its way not just to other planets but other solar systems as well. Calculations by Tetsuya Hara and his colleagues at Kyoto Sangyo University in Japan show that a surprisingly large amount of life-bearing material ended up not on the Moon and Mars, as might be expected, but the Jovian moon Europa and the Saturnian moon Enceladus also received tons of life-bearing rock from earth. Even more amazingly, calculations suggest that most Earth ejecta ended up in interstellar space and some has probably already arrived at Earth-like exoplanets orbiting other stars. Hara estimates that about a thousand Earth-rocks from this event would have made the trip to Gliese 581, a red dwarf some 20 light years away that is thought to have a super-Earth orbiting at the edge of the habitable zone, taking about a million years to reach its destination. Of course, nobody knows if microbes can survive that kind of journey or even the shorter trips to Europa and Enceladus. But Hara says that if microbes can survive that kind of journey, they ought to flourish on a super-Earth in the habitable zone (PDF). 'If we consider the possibility that the fragmented ejecta (smaller than 1cm) are accreted to comets and other icy bodies, then buried fertile material could make the interstellar journey throughout the Galaxy,' writes Hara. 'Under these circumstances fragments could continue the interstellar journey and Earth origin meteorites could be transferred to Gl 581 system. If we take it as viable, we should consider the panspermia theories more seriously.'"
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Scientists Study Trajectories of Life-Bearing Earth Meteorites

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  • by circletimessquare (444983) <circletimessquare&gmail,com> on Thursday April 12, 2012 @08:23AM (#39656149) Homepage Journal

    so the culmination of mankind's civilization, scientific efforts, and technological achievements, is to go to some exoplanet, only to find some foot fungus some dinosaur had long before mankind ever appeared?

  • by Anonymous Coward on Thursday April 12, 2012 @08:41AM (#39656255)

    I think God did it as stated in the Bible, but since time is relative to Gods perspective and it didn't say there were NO dinosaurs. I guess he just threw a rock to see what would happen at some point. Probably wasn't necessary to mans salvation to give all the details.
    Makes more sense than some hokum about panspermia. If a rock hit, no one knew which way the ejecta blew and with such great distances and so many degrees of freedom to take, it is sooooo doubtful it made it anywhere immediately useful to seed anything anywhere or even travelled to some distant system and then land somewhere useful there.
    Must be kinda like throwing a handful of marbles over the edge of the Grand Canyon and hoping one lands in someones water-glass somewhere below, maybe.

  • by Anonymous Coward on Thursday April 12, 2012 @10:27AM (#39657453)

    so the culmination of mankind's civilization, scientific efforts, and technological achievements, is to go to some exoplanet, only to find some foot fungus some dinosaur had long before mankind ever appeared?

    ... where it then evolved further and began teaching creationism in classrooms.

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