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Earth Under Threat From Dark Comets

An anonymous reader writes "Comets could be the most significant impact hazard to Earth, with sky surveys underestimating the number that are potentially devastating by a factor of between 10 and 100, UK astrophysicists say."

12 of 149 comments (clear)

  1. Seriously? WTF? by zappepcs · · Score: 4, Insightful

    "Comets could be the most significant impact hazard to Earth

    Just what are the "other" impact hazards? I'm very curious about this.

    1. Re:Seriously? WTF? by meringuoid · · Score: 4, Informative
      Just what are the "other" impact hazards? I'm very curious about this.

      Asteroids.

      Asteroids orbit nearer the Sun, and many of them have paths that cross Earth's orbit quite frequently. They're a menace all right, but a menace that can be mapped and measured. Comets on the other hand have long, highly elliptical orbits that carry them far from the Sun. Though any given comet won't pass near the Earth anywhere near so often, they exist in colossal numbers, and for all we know one could come barrelling out of the dark to kill us all next month. We could in principle track every rock of dangerous size in the inner solar system. We haven't a prayer of tracking all the comets.

      --
      Real Daleks don't climb stairs - they level the building.
    2. Re:Seriously? WTF? by Anonymous Coward · · Score: 4, Funny

      sperm wales and pertunias...

  2. Re:Slashdotted by morgan_greywolf · · Score: 5, Informative

    Here we go, try this article from New Scientist, which has the same story.

    Hazardous comets and asteroids are monitored by various space agencies under an umbrella effort known as Spaceguard. The vast majority of objects found so far are rocky asteroids. Yet UK-based astronomers Bill Napier at Cardiff University and David Asher at Armagh Observatory in Northern Ireland claim that many comets could be going undetected. "There is a case to be made that dark, dormant comets are a significant but largely unseen hazard," says Napier.

    The article goes on to say that "dark comets are not unheard of. They occur when an 'active' comet's reflective water ice has evaporated away, leaving behind an organic crust that only reflects a small fraction of light."

  3. I Call FUD Anyway by mfh · · Score: 5, Funny

    It's down for a sinister reason! They don't want us to READ the articles and become informed of the truth!!!

    Also, why the racism? Just because the comets are DARK doesn't mean they are evil. RACISTS!

    --
    The dangers of knowledge trigger emotional distress in human beings.
  4. Re:Another reason for fear by norppalaho · · Score: 5, Funny

    ...If I have to start worrying about the sky falling on me...

    Vitalstatistix, Is that you?

    --
    One of the coolest sites, ever: zombo.com
  5. DCC Trading by Anonymous Coward · · Score: 5, Funny

    My greatest fear is that people will view this as something that they have no control over, thus inducing a sense of complacency. Complacency kills!

    But there is hope. I propose a Dark Comet Credit (DCC) trading system, whereby planets that are in danger of being struck by dark comets purchase dark comet credits from planets that aren't in danger.

    It may not be a perfect plan, but it's better than doing nothing.

  6. don't be so judgmental by jollyreaper · · Score: 4, Funny

    Just because these comets hang out in the furthest, coldest reaches of the solar system, don't reflect light all that well and listen to cradle of filth, that doesn't make them all dark! Goth, maybe, but not dark. You just don't understand them.

    --
    Kwisatz Haderach
    Sell the spice to CHOAM
    This Mahdi took Shaddam's Throne
  7. Re:Slashdotted by dkf · · Score: 5, Informative

    Organic != made by life. Means nonmetals, so Carbon, Nitrogen Sulfur and related compounds.

    It specifically means Carbon. There's really quite a bit of it about in space, and the process of evaporating off all the ice from the comet will mean that that which is there has been thoroughly concentrated to make something rather like soot. Such materials, especially in ultra-low gravity environments (so preventing the collapse of complicated micro-strucutres), are incredibly black, making the comet harder to see than a black cat in a coal cellar. At night with no torch.

    The New Scientist article goes on to mention that the best hope of spotting these things may be in the infra-red range, as they'll be absorbing all the sunlight that falls on them and reradiating it. Sounds tricky to me, but just might work...

    --
    "Little does he know, but there is no 'I' in 'Idiot'!"
  8. No torch? by PeeAitchPee · · Score: 4, Funny

    are incredibly black, making the comet harder to see than a black cat in a coal cellar. At night with no torch.

    Who uses torches in their "coal cellar"? What are you looking for, Frankenstein? ;-)

    1. Re:No torch? by Ray · · Score: 5, Funny

      Way too subtle. Remember, speakers of "the Queen's English" require giant, cartoon stomping feet to indicate humorous content is about to follow.

  9. Oblig.... by SIR_Taco · · Score: 4, Funny

    Shouldn't we put brown paper bags over our head or something?
    If you like.
    Will it help?
    No.

    --
    I say don't drink and drive, you might spill your drink. Before you get behind the wheel just stop and think.