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Space Science

Tracking Possible Earth-impacting Asteroids 52

EccentricAnomaly writes "NASA's Near-Earth Object program has announced the Sentry automatic impact monitoring program. Check out this impact risks page showing current asteroids that might impact the Earth. The current highest risk object is 2002 CU11 which has a 0.001% impact probability in 2049... an impact that would be 58,000 megatons."
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Tracking Possible Earth-impacting Asteroids

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  • This is what government is for. If we spent half the money on this that we spend on those two horrible asteroid movies, we wouldn't have a thing to worry about.
  • ...to say "58,000 Megatons" vs "58 Gigatons".
    I mean hey, a Gigaton is big, but a 1000 Megatons? Whoa, you're talking some serious tonnage there!
    Personally I'd go for the max fear-factor and say 58,000,000 tons...
  • The best candidate is half a mile wide, it should be a fairly quick and painless death.
  • Alright! For the last two years, I have been looking for a reason to keep the bomb shelter in good repair. Before I was born, it was there in case of nuclear war. Then, the cold war ended, and there was a time when the shelter served no purpose. Thank the gods for y2k, there was once again a reason to keep it clean. But the computers continued to work, damn it! I damn well want to us my bomb shelter! Now, I have 47 years of anticipation. Well, its better than nothing, I suppose.
  • The article claims that the probability of impact is 0.001

    The site, however, gives an impact probability of 1.0e-5, which is 0.00001.

    I take it someone failed to read the article carefully before submitting.
  • The probability of impact for CU11 object is actually 0.0021% which is twice as scary. The 0.0021% figure comes from adding the probablities of all of the guessed trajectories.

    For those of you scratching your heads about it being 0.0021% instead of 0.000021 (2.1e-5) its because you have to multiply by 100 when converting a raw probablity to a percetage chance.
  • Sentry automatic impact monitoring system... Damn thing better monitor the impacts automaticly. It's not like there will me any people to care after an impact with an energy equil to the detonation of 52,727,272,727,272,727 grams of trinitrotoluol!!!
  • But it would take much less TNT to wound a Gorn.
  • by isorox ( 205688 )
    So in 47 years we might die.

    Tahts scary. Not the dying bit, the fact its 47 years - by far the most common number in the universe.
    • by Perdo ( 151843 )
      Don't feel bad, next year it will be 46 years and you can lay your numerology on the 4/7/2047 earthquake or the 47 straight razor causing your demise.
    • Just out of curiosity, did you or anyone you know ever go to Pomona College in Claremont, California?
      • nope, but I remember reading about pomona from the abundance of 47 in trek
        • yeah. while i no longer go there, i did for a couple years. several years ago, one of the stats profs "proved" that all numbers were equal to 47. it caught on. it is now seen as a sacred number there, and as several pomona grads went on to write for star trek: the next generation. in another bit of trivia, the borg are named after oldenborg dorm, a dorm into which people go in, but do not come out.
  • Meteoric Death (Score:3, Interesting)

    by Perdo ( 151843 ) on Wednesday March 13, 2002 @03:36AM (#3155131) Homepage Journal
    I'm sure these guys have the metric/standard thing fixed for these trajectory calculations. I mean it is NASA and they would never make a silly mistake like that right? um.. right?

    How many times has your computer spit out the wrong answer but you accept it as true, just to find out later that you fed it the wrong data? I would sort of like to see them put at least as much effort into tracking earth crossing asteroids as say... modeling nuclear explosions.

    I mean the JPL's computer is number 374 on the top 500 list not number 1, with number 5 acting as a glorified graphics card.

    ASCI Blue, a 32,524,800,000-transistor graphics card: 50 million dollars
    GeForce 4, 63,000,000-transistor graphics card: 450 dollars.
    Time for ASCI blue's power to be available at retail following Moore's law: 14 years

    Amateur computer enthusiasts and astronomers saving the world: priceless.
  • by leviramsey ( 248057 ) on Wednesday March 13, 2002 @06:54AM (#3155563) Journal

    Bruce Willis will be 94 in 2049! How will we get someone that old into space to blow up the asteroid?

  • by olman ( 127310 )
    Woo, there's one with 1.8% probability of hitting us! But it's only 40 meters.. I wonder if they compensate for atmospheric burn on those "small" rocks.

    With the annoying inverse square law for radars, you're be pretty much reduced to optics. Plenty of space to eyeball this side of pluto orbit.. Anyone actually looking to the right direction with a high-power telescope is pretty low, isn't it?

    So what's the probability of the "Big Mama" showing up on the threat list with any kind of meaningful lead time?
    • I doubt a 40-meter meteor would burn much, relative to its size, on the way down.

      I hate to say it, but an impact from one of these "small" rocks might be a good thing. Get a nuke-size detonation (I'm guessing a 40-meter rock would be a Hiroshima-equivalent?), preferably but not necessarily in an unpopulated area, and the world's governments might wake the fuck up to how serious the danger is, and the fact that an active space program that doesn't have to plan its launches months in advance is our best defense.
    • I assume you are referring to 2000 SG344, in which case the cummulative probability of impact is .18% for a hit. You missed a decimal in there. Further inspection will show that it has a 7.4e-04 or .074% chance of a hit in 2071 which would yield a 1 mega ton explossion.
    • With the annoying inverse square law for radars, you're be pretty much reduced to optics

      ... and the major problem with "eyballing it" (well.... CCD'ing it anyway) is that a lot of Kuiper belt objects have an albedo of ~0.03-0.05. That's about the same as printer toner. Hmmm.... let's look for the black rock 10km across that's 2x10^9 km away.
      Asteroids are a little brighter, but it still takes a LOT of patience, comparing multiple shots of the same piece of sky to look for the movers and THEN try to calculate a trajectory

      MAB

      • ... and the major problem with "eyballing it" (well.... CCD'ing it anyway) is that a lot of Kuiper belt objects have an albedo of ~0.03-0.05. That's about the same as printer toner.

        That bad? I always kind of visualized asteroids as being gray-ish tone. Got suckered by SF TV, no doubt. In any case.. How exactly *do* they detect/track those objects if the albedo's so laughable? you'd have to crank the magnification way up to be able to "see" them, no? Something like Hubble's cool, but how much of the sky globe does it "see"? 1*10^-6 ? Even if we actually start building probes to go and look for the damn things, you'd need way way too many of them!

        I don't really know about the spectrum of radiation from Sun, but I expect visible light's not necessarily the most optimal wavelenght to look for, correct? Reflection from black rocks-wise. At least those rocks should be warmer than the background radiation?

  • Assuming the submitter did his/her math correctly...

    I know 0.001% isn't *that* great a probability (1 in 100,000), but it's a little daunting to think that the probability of Earth being smacked by a huge asteroid during my lifetime is about 1000 times better than my chances of winning the lottery.

    (And yeah, that's just that one asteroid, so the real chance would be even a bit higher.)

    Gives new meaning to "live for today", eh?
  • If I remember there was an article a few years back that said we only are able to track a small percentages of asteroids in orbits that come near the earth. Now perhaps technology has improved quite a bit in the past couple of years, but it only takes 1 big one to kill most of the earths population. What I'd really like to hear is not the percentage chance of those we know about hitting us, but instead the percentage that we dont know about.
    • From what I've read, the large majority of the asteroids we don't track are too small to be picked up with the current technology. Now whether or not this means that they would still destroy civilization as we know it if they hit the Earth I don't know, but I think that the smaller they are, the better.
  • There are probably two choices if a large comet or meteor is on a collision course with earth: * Bend over and kiss your a** goodbye or * http://personals.galaxyinternet.net/tunga/
  • The cummulative probability cited for 2002CU11 is states as 2.1e-05. The expression "e" is not the same thing as base "ten". This works out to 1.4% probability of impact.
  • What I want to know is how they take into account the smaller asteroids that they cannot track. Every once in a while they must collide with tracked ones, so how do they provide for that in their tracking program? Or do they not worry about it at all, and just revise their courses when a visible deviation is seen...? Hmmm...

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