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Scientists Study Trajectories of Life-Bearing Earth Meteorites

Posted by samzenpus on 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.'"

12 of 199 comments (clear)

  1. Panspermia by The+Evil+Atheist · · Score: 5, Insightful

    If we take it is viable, we should consider the panspermia theories more seriously.

    Only as a possible answer to the origin of Earth's life. It still doesn't answer the origin of life itself, wherever it may have started.

    --
    Those who do not learn from commit history are doomed to regress it.
    1. Re:Panspermia by olsmeister · · Score: 5, Insightful

      No, but it could answer the question of how life managed to arise here on earth in a relatively short period of time, and would also exponentially expand the potential area we consider when we think about places that could have been suitable, both chemically and environmentally.

    2. Re:Panspermia by fatphil · · Score: 5, Interesting

      I've seen arguments on a scientific mailing list in the last few days that this paper is based on false assumptions. It has assumed (too high) values for masses based on (too low) values for velocities based on the assuption that the meteorites are aiming at earth under its gravity, rather than aiming for the sun under its gravity and accidentally hitting earth on its way towards the sun.

      If you change the masses downwards to what they should be, then the chance of them getting through an atmosphere without breaking/burning up and denaturing all its alleged payload become minuscule.

      --
      Also FatPhil on SoylentNews, id 863
    3. Re:Panspermia by socialleech · · Score: 5, Informative

      You should read about the Miller-Urey experiment.

      For those to lazy to read about it, scientists have created all of the amino acids required by life, using nothing but inorganic compounds, by recreating the atmospheric conditions of early Earth.

      Life may or may not have originated on Earth, but we tested it and found that it could have. If it could have been created here, using nothing but the things that the universe placed here, why couldn't it have also developed else where? Are we the seeding planet of the galaxy/universe? Were we seeded? Or is life just incredibly common?

    4. Re:Panspermia by Migraineman · · Score: 4, Interesting

      I guess he just threw a rock to see what would happen at some point.

      So your version of God isn't all-knowing and all-powerful? I'm not buying that a God who is capable of creating billions of planets, stars, and systems wouldn't have a firm grasp on probability and interstellar trajectories. Maybe we should consider that your God is bored (he does control everything, right?) and has set up the universe as a giant Rube Goldberg machine for His entertainment. He would have to accede to non-interference for the exercise to have any value.

  2. that's depressing by circletimessquare · · Score: 5, Funny

    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?

    --
    intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
  3. Sub 1cm Ejecta by RivenAleem · · Score: 4, Interesting

    How do objects this size survive the trip through the destination planet's atmosphere?

  4. Worth a read, but ... by Trapezium+Artist · · Score: 5, Interesting

    I've made a quick scan of the underlying academic article by Hara et al., along with one of my colleagues in a meeting here, who is closely involved in the issue of planetary protection (i.e. making sure that our spacecraft don't "pollute" the solar system bodies they fly to and land on).

    Of course, this is a known issue in general: after all, there are meteorites on Earth which we know came from Mars, so the converse is obviously possible. But extending this to moons of Jupiter, Kuiper Belt objects, and even exoplanetary systems, and finding that a significant number of Earth rocks may have been dumped there is interesting. So, the article is worth a more careful read.

    However, my antennae were sent into a state of high agitation when I saw that the article has been posted on the arXiV following its having been accepted to the infamous Journal of Cosmology. We've discussed that here before: I invite you to view the journal website (easily found by googling) and decide for yourselves how reputable it is.

    Which raises the question of why Hara et al. chose to publish there. That I can't answer, obviously, but will keep it firmly in mind as I read the paper in more detail.

  5. Re:Place Bets Here by jochem_m · · Score: 4, Insightful

    and the fact that it's more like hitting any of a dozen cockroaches with a million needles...

  6. You are exceptional by exploder · · Score: 5, Insightful

    Astounding! With just a few minutes of thought and your superior intuition, you've dismissed the result of careful calculation and decades of training on the part of this group of scientists. Imagine what a genius of your magnitude could accomplish from within the scientific system...it truly staggers my humble intellect! But I'm sure you're working on much more important things.

    --
    Yo dawg, I heard you like the Ackermann function, so OH GOD OH GOD OH GOD
  7. Martin Lo's low energy trajectories by mattr · · Score: 4, Informative

    Actually Martin Lo discovered low energy gravitational paths or "superhighways" that would allow objects like space probes and maybe rocks to travel all around the solar system without power. These calculations were used in the Genesis probe NASA project IIRC.
    http://en.wikipedia.org/wiki/Interplanetary_Transport_Network
    http://genesismission.jpl.nasa.gov/gm2/team/people/lo/interview1.htm

  8. Re:Don't you mean... by Anonymous Coward · · Score: 5, Insightful

    Just once I'd like to see an origin-of-life article on Slashdot without atheists dragging religion into the discussion.