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Asteroid Will Make Close Pass To Earth

The Bad Astronomer writes "News is starting to spread about a small 45-meter-wide asteroid called 2012 DA14 that will make a close pass to Earth on February 15, 2013. However, some of these articles are claiming it has 'a good chance' of impacting the Earth. This is simply incorrect; the odds of an impact next year are essentially zero. Farther in the future the odds are unclear; another near pass may occur in 2020, but right now the uncertainties in the asteroid's orbit are too large to know much about that. More observations of DA14 are being made, and we should have better information about future encounters soon."

36 of 119 comments (clear)

  1. 45 meters? by Anonymous Coward · · Score: 2

    Would any of that thing even reach the ground before burning out during atmospheric entry?

    1. Re:45 meters? by JordanH · · Score: 2

      IANAA (Astrophysicist), but I believe asteroids of that size would reach the earth. Depending what it's made of, it could break into a lot of pieces, though.

      This is a pretty small asteroid and (again, I'm no expert) but its orbit means that it wouldn't have a great relative velocity if it did strike earth (nothing like a comet, by comparison). There were some estimates on the damage it would do if it were to strike in the referenced article and this doesn't seem to be a major concern.

    2. Re:45 meters? by KingofSpades · · Score: 5, Interesting

      What do you think of this ?
      It was made made by a 45 meter impactor.
      Yes, A 45 METER IMPACTOR.

    3. Re:45 meters? by DanielRavenNest · · Score: 2

      Yes, depending what it is made of. Check out this one at the American Museum of Natural History:

      http://farm3.static.flickr.com/2189/2106429655_9edb74118a.jpg

      The Earth's atmosphere is equivalent to 10.3 meters of water in mass per area. Re-entry heating gets split between the meteorite and the air it is traveling through. When the meteorite mass per area is higher than the equivalent mass per area of the atmosphere, it tends to not pick up enough heat to melt entirely or drag to stop. Asteroid density varies depending on type from near water to near steel (1 to 8). Dynamic pressure slamming into the atmosphere can definitely fragment an asteroid, but that deposits all the kinetic energy in an airburst. This size rock can generate 0.5 to 4 Megatons of equivalent energy. It either goes into the air or into the gound. Either way you get a shock wave far beyond the size of the rock.

    4. Re:45 meters? by Solandri · · Score: 3, Informative

      The asteroid which made Meteor Crater in Arizona is estimated to have been about 50 meters across. About half of it is thought to have burned up before impact.

    5. Re:45 meters? by Solandri · · Score: 2

      Doesn't really matter. If half its mass ablated away, a rock 50m in diameter would be 40m in diameter at impact. 0.5^(1/3) = 0.7937, or half the mass = 79.4% the original diameter.

    6. Re:45 meters? by jovius · · Score: 3, Funny

      See, meteorites create tourist attractions. The larger the crater the bigger the cash flow. Meteorite impacts are good for the economy.

  2. Want to see more? by NoZart · · Score: 5, Funny

    Seeing more and more reports of near passes. Frigging Bugs must be out of target practice and are homing in on us! Get NPH!

    1. Re:Want to see more? by BeerCat · · Score: 5, Funny

      Service guarantees citizenship

      --
      "She's furniture with a pulse"
    2. Re:Want to see more? by NoNonAlphaCharsHere · · Score: 5, Funny

      I'd like to know more.

  3. Of course it won't hit us by NoobixCube · · Score: 4, Funny

    The world ends toward the end of this year, duh! Of course the chance of hitting the Earth is 0%, because we won't be here!

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    1. Re:Of course it won't hit us by Xtifr · · Score: 4, Funny

      I think you misunderstand the disaster that's coming. When the Mayan calendar ends, all computers that use the Mayan calendar will crash, world-wide. Worse yet, unlike Y2K, where we were able to drag old Cobol programmers out of retirement to fix the problem, experts in Mayan computers are all extinct. So we're all doomed! Except for those of us who don't use Mayan computers. :)

  4. Re:Good riddance by wanzeo · · Score: 5, Insightful

    Not this time, the article says it is expected to pass between us and Geostationary orbit. Even if it does impact intact, the worst the damage could be would be comparable to the Tunguska event.

    Depending on location, it could be very bad, but not an extinction event. You are right though, if it was bigger, we would be screwed. Not even Bruce Willis could save us with one year notice.

    If it does hit, maybe it will convince those with the cash that asteroid defense is a worthwhile expense.

  5. JPL impact risk table by Anonymous Coward · · Score: 5, Informative

    TFA contains a link to an predicted impact table of DA14 with earth, going some 50 years into the future. The likelihood of each impact is rather small, and the cumulative probability of any impact is computed as 2.2e-04 (about 1 in 5000 - not alarming, but not exactly negligible IMO).

    Here's what I don't understand: the first entry in the chart, corresponding to the next risk event, is in the year 2020. What happened to Feb 2013?

    1. Re:JPL impact risk table by jaa101 · · Score: 3, Informative

      Since we can predict the next (2013) close approach very accurately we're very confident it will be a miss. Therefore that approach doesn't rate a mention in the table.

      The trouble comes in that, while we know the 2013 approach distance will be greater than 0km from the surface (>6400km from the centre) there's still some uncertainty. The earth is massive and the close approach will cause a relatively large change in the orbit of DA14. The size of the change is inversely proportional to the square of the approach distance. Thus even a small uncertainty for 2013 results in a large uncertainty for subsequent approaches. Celestial billiards at work.

  6. It's not "simply incorrect" by Anonymous Coward · · Score: 2, Interesting

    Whether the asteroid has a "good chance" of hitting the earth depends on how you define "good chance," which does not have an accepted standard definition.

  7. Re:Wait... 45 METRES?! by regdul · · Score: 3, Insightful

    Don't know if trolling It's about energy – you would need a big pebble to do any damage if you were to throw it by hand, but accelerate it and it does some damage. A bullet is smaller than a pebble

  8. Re:Good riddance by Anonymous Coward · · Score: 3, Insightful

    If it does hit, maybe it will convince those with the cash that asteroid defense is a worthwhile expense.

    But it isn't. The chance of anything important being hit is almost nil, while defending from asteroids is extremely expensive. It just isn't cost-effective.

  9. pfffffff..... by butilikethecookie · · Score: 4, Funny

    What's up with all of these close passes? Hey universe! Grow some nuts and actually hit us with one, you pussy!

    1. Re:pfffffff..... by amoeba1911 · · Score: 2

      Yeah, it's such a tease. It's like a hot girl waving at you at a bar, and then you realize she's waving at a guy behind you.

      I say enough with the tease. No more close passes. Either hit this, or go away.

  10. Cost effective?!? by Anonymous Coward · · Score: 5, Insightful

    If it does hit, maybe it will convince those with the cash that asteroid defense is a worthwhile expense.

    But it isn't. The chance of anything important being hit is almost nil, while defending from asteroids is extremely expensive. It just isn't cost-effective.

    Just look at our wars on "Terror" and "Drugs". Do you honestly think cost effectiveness is ever considered?

    Now defending from asteroids won't be politically feasible until we actually get hit by one - when people can actually see it and experience the impact, death and destruction. Some millions of years old crater in a desert is nothing.

  11. Re:Good riddance by K.+S.+Kyosuke · · Score: 2

    Since when is a rocket with a nuke more expensive than the global civilization that we have?

    --
    Ezekiel 23:20
  12. Re:Big sky, little rock by oodaloop · · Score: 5, Funny

    Oh thank goodness an anonymous coward has determined there's nothing to worry about. Hey everybody! Everything's OK!

    --
    Tic-Tac-Toe, Global Thermonuclear War, and relationships all have the same winning move.
  13. Re:Good riddance by Anonymous Coward · · Score: 5, Insightful

    Trouble is, a single rocket with a single nuke isn't likely enough to fix a civilization-destroying rock.

    Also, given the choice between practically any expenditure and world civilization, of course it's worthwhile. But by the time we get that choice, it's too late to do anything. At the moment, it's something like "building and maintaining a rocket with a nuke" for "1 in a million annual risk to global civilization".-- you can't just say that such a rock is eventually inevitable, because asteroid defense isn't something you buy once and put on the shelf in addition to the upkeep and periodic replacement of weapons, there's the cost of a concerted monitoring program to detect a threat early enough and with an accurate enough orbital solution that the gentle tap of a nuke will eliminate the risk.

    It's not easy to come up with actual numbers, but once you factor in the possibility (IMO likelihood) that civilization may well end long before such an impact, it would not be entirely surprising to find that it's actually economically saner to hope for the best than to make preparations.

    (It's analogous to a civilian in low-crime areas considering the purchasing and wearing Type III body armor -- the cost, discomfort, and hassle of wearing it for a day is certainly less expensive than dying from a rifle shot, but the odds of ever encountering such a situation are so low it's not worthwhile.)

  14. Misleading Article Title by sociocapitalist · · Score: 2

    Asteroid Will Make Close Pass To Earth != "the odds of an impact next year are essentially zero"

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    blindly antisocialist = antisocial
  15. Re:Good riddance by macraig · · Score: 2

    I suspect you like watching things blow up, but that's not really the wisest choice here. Much better would be an impactor with very high mass - perhaps a depleted uranium core - and low relative velocity: slow enough to contact the asteroid without shattering it and massive enough to nudge its trajectory and keep nudging it for a while. Post-contact booster rockets might help further. It's not something you launch in the eleventh hour, though.

  16. Re:Good riddance by TheRaven64 · · Score: 2

    It doesn't just need to be a rocket, it needs to be a really big rocket. To deflect something potentially civilisation-destroying, you want to do it as early as possible. Inside lunar orbit is much too late. That means that you need to get a rocket out to it, and then match velocities (just ramming it won't be enough) and deliver the explosive to a sensible location. Ideally, you want to attach to the side and push it, rather than try to blow it up. We're talking something that would make the Apollo rockets look small...

    --
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  17. Re:Wait... 45 METRES?! by KingofSpades · · Score: 2

    even though we're about 26,000 mi in diameter

    Who are *we* ?

  18. Re:Next pass? by mcswell · · Score: 2

    Provided the asteroid's mass is much smaller than the Earth's--which it is, unless it's made of neutronium--then its deflection does not significantly depend on its mass.

  19. Re:Good riddance by rubycodez · · Score: 3, Interesting

    The last 6 mile diameter/civilization-destroying-sized thing was 65 million years ago. we won't be human in 65 million years, we could as well be animal or rodent by that time. Clearly we should spend $0 on the problem. As for city-destroying-sized things, odds are any will just land in uninhabited area. If a city does get hit, well, sucks to be them.

  20. Re:Good riddance by hcs_$reboot · · Score: 2

    it is expected to pass between us and Geostationary orbit

    With a bit of luck it will clean out a few dead satellites on the way

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  21. Re:Let's get this to scale... by Xocet_00 · · Score: 3, Insightful

    But the Earth is much larger than a bowling pin. I'd say that passing passing within a few Earth radii is of us is a fair definition of a near miss.

  22. Re:Wait... 45 METRES?! by garyebickford · · Score: 2

    If it hit the ocean anywhere near land, it would still cause significant devastation. In "Lucifer's Hammer" by Larry Niven and Jerry Pournelle, a much larger object struck the Pacific Ocean - IIRC a mile in diameter. At 30,000 MPH relative, about 8.3 miles per second, that large object went through the depth of the Pacific in something less than one second, vaporizing cubic miles of water and causing a tsunami a couple thousand feet high, striking LA and washing over the mountains into the Central Valley. This one is a tiny fraction of that one, but I suspect (without doing any math) that if it hit within a few miles of a coastline it might easily displace a volume of water equivalent to the crater it would generate on land, thereby causing a significant tsunami, and it would vaporize enough to change the weather for a year or two.

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  23. Re:Good riddance by Skal+Tura · · Score: 2

    Anything that massive would suck all countries GDP for the next 100 years to get into orbit.

  24. Re:Good riddance by RandomAdam · · Score: 2

    Isn't that sometimes you roll a 20 on your confirm roll?

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    @Random_Adam

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  25. Re:Good riddance by buchner.johannes · · Score: 4, Informative

    Touching/Landing on asteroids is difficult because they have very complicated structures and rotations. The best way to deflect an asteroid is not by nukes or what you suggest, but by spraying it white (solar radiation pressure) or parking a mass (e.g. 1t) with a ion drive next to it.

    http://www.physorg.com/news/2011-11-deflect-asteroid.html
    https://en.wikipedia.org/wiki/Asteroid-impact_avoidance#Collision_avoidance_strategies

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