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Space Science

Nearby, Recent Interplanetary Collision Inferred 88

The Bad Astronomer writes about a new discovery by the Spitzer Space Telescope, which detected signs of an interplanetary smashup only 100 light-years from here, and only a few thousand years ago. There's a NASA-produced animation of the collision between a Mercury-sized planet and a moon-sized impactor. The collision's aftermath was detected by the presence of what are essentially glass shards in orbit around the star. Here's NASA's writeup.
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Nearby, Recent Interplanetary Collision Inferred

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  • by olsmeister ( 1488789 ) on Monday August 10, 2009 @08:41PM (#29018263)
    the guy posting the blog states: "the shock wave ring travels around the planet as shown, but when the ring converges on the point opposite the collision point, there would be a huge explosion and a vast plume of material launched into space. No one ever puts that in their animations"

    I thought the same thing when I watched the video - there would be a godawful explosion at the antipode
  • by JuzzFunky ( 796384 ) on Monday August 10, 2009 @09:10PM (#29018447)
    It is interesting that the animation shows a direct hit head on collision rather than a glancing blow. Most of matter from the planet and impactor seems to combine into a single mass. Would a glancing blow that shatters the impactor result in more debris?
  • by denzacar ( 181829 ) on Monday August 10, 2009 @10:13PM (#29018805) Journal

    There is a place. It is a place where broken rocks ring a red sun.
    Several centuries ago, we discovered a race of arthropod-like creatures called Whilles, with whom we could not deal.
    They rejected friendly overtures on the parts of every known intelligent race. Also, they slew our emissaries and sent their remains back to us, missing a few pieces here and there.
    When first we contacted them, they possessed vehicles for travel within their own solar system. Shortly thereafter, they developed interstellar travel.
    Wherever they went, they killed and they stole and then beat it back home.
    Perhaps they didn't realize the size of the interstellar community at that time, or perhaps they didn't care.
    They guessed right if they thought it would take an awfully long time to reach an accord when it came to declaring war on them.
    There is actually very little precedent for interstellar war. The Pei'ans are about the only ones who remember any..
    So the attacks failed, what remained of our forces were withdrawn, and we began to bombard the planet.
    The Whilles were, however, further along technologically than we'd initially thought. They had a near-perfect defense system against missiles.
    So we withdrew and tried to contain them. They didn't stop their raids, though.
    Then the Names were contacted, and three worldscapers, Sang-ring of Greldei, Karth'ting of Mordei and I, were chosen by lot to use our abilities in reverse.
    Later, within the system of the Whilles, beyond the orbit of their home world, a belt of asteroids began to collapse upon itself, forming a planetoid.
    Rock by rock, it grew, and slowly it altered its course. We sat, with our machinery, beyond the orbit of the farthest planet, directing the new world's growth and its slow spiral inward.
    When the Whilles realized what was happening, they tried to destroy it.
    But it was too late. They never asked for mercy, and none of them tried to flee. They waited, and the day came.
    The orbits of the two worlds intersected, and now it is a place where broken rocks ring a red sun. I stayed drunk for a week after that. []

  • by StCredZero ( 169093 ) on Monday August 10, 2009 @10:54PM (#29019087)

    There are probably more efficient ways of wiping out life than pouring on the order of 10^30 joules into accelerating a gigantic impactor.

    Put the same energy into lots of small relativistic impactors. Craft the trajectory so that the acceleration phase is masked by nearby stars. Distribute the impactors so that all orbital installations and both sides of all inhabited bodies are blanketed with enough energy to raise the temperature to 500 degrees celsius for all biomes. Time them, so that they all arrive at the same time. The victims will have only minutes of advance warning, if any at all. (Idea from _The Killing Star_)

  • by pintpusher ( 854001 ) on Monday August 10, 2009 @11:05PM (#29019153) Journal
    I immediately wondered if there were any such antipodal geology evident on earth. A quick google turned up this presentation [] which is pretty darn interesting. IANAGeologist, and can't speak to the accuracy of the claims, but it's still darn cool!

Q: How many IBM CPU's does it take to execute a job? A: Four; three to hold it down, and one to rip its head off.