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Keeper of the Objects

Posted by michael on from the wipeout dept.

cEnTiBeE writes that this is "not about the Matrix," but rather about Near Earth Object tracking. "It's accomplished by a staff of 2.5 people watching to see when any 'vermin of the sky' plan to pay earth a visit. This piece titled Keeper of the Objects is in the August '03 issue of Scientific American."

5 of 144 comments (clear)

  1. Re:Joy by russ_allegro · · Score: 5, Informative

    Actually there is a lot more than 2.5 watching the skies. The Minor Planet Center takes data from amatuers as well as their own automated telescope. It is true that the MPC keeps and processes the data. Although ametuers are known from time to time to do their own orbital calculations.

  2. Actual Frequency of Impact by thelandp · · Score: 5, Informative
    There's a relationship between asteroid size and predicted frequency of impact.

    10m - every 1-5 years

    100m - every 1000 years

    1km - every 100,000 years

    The Tunguska blast of 1908 was a roughly 100m asteroid, hitting land.
    If it had been an ocean impact, it would have produced significant tsunamis.
    On the remote chance it had landed right on top of a large city, then the city would be completely gone.

    A 1km asteroid would wipe out a moderate US state, or create tsunamis that travel to most of the globe. Either way it would affect the climate due to dust clouds.

    The observational population census for Earth crossing objects is only complete for objects in the 8-kilometre diameter range (such as 1627 Ivor) or larger. The detection completeness for 1 kilometre range is estimated to be in the region of 12%.

    (further reading is here)

    Maybe it's worthwhile upping the budget so we can track all of them down to 1km ?

    --

    -- the only thing we have to fear is really scary things
    1. Re:Actual Frequency of Impact by bravehamster · · Score: 5, Informative

      The Tunguska blast of 1908 was a roughly 100m asteroid, hitting land.

      Kinda a' nitpick, but the Tunguska object didn't hit land, it was an air-burst. That's the reason there isn't a huge crater there now. It flattened all the trees for hundreds of square miles, but in the very center of the blast, no crater. Stumped a bunch of scientists for a good long while. Air-burst detonations have a larger area of immediate effect (i.e. flattened by the blast wave), but their global effect is less than ones that actually impact. Either way you get lots of knocked over trees and some pretty sunsets.

      --
      ---- El diablo esta en mis pantalones! Mire, mire!
    2. Re:Actual Frequency of Impact by mikerich · · Score: 3, Informative
      The Tunguska blast of 1908 was a roughly 100m asteroid, hitting land.

      It was at most 50 metres across and made largely of ice, it would never have made it to the surface.

      If it had been an ocean impact, it would have produced significant tsunamis.

      At 15 megatonnes it wouldn't have raised much more than a ripple. The US exploded larger bombs at sea level.

      The rest of your point is well taken though, although you left out one bit. Would Dubya, Putin or our little poodle in the UK wait to confirm the source of an explosion that took out one of their cities before launching a nuclear attack against their evil guy of the week?

      Best wishes,
      Mike.

  3. Re:Joy by joebeone · · Score: 3, Informative

    As an astronomer, I can say with confidence that those 2.5 people probably do a lot more of technological babysitting than actual not-enough-time-in-the-day work... objects are found by computer software that compare image residuals (subtractions of images separated by a day or two)... fast moving things are closer to earth and may warrant follow-up with a larger 'scope.