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Earth's Asteroid Risk Downgraded

Posted by simoniker on from the i-was-worried-for-a-while dept.

xanthines-R-yummy writes "Relax, everyone - the risk of a gigantic asteroid colliding with Earth just got smaller! Nature reports: "A new survey revises down the likelihood of a massive asteroid hitting the Earth by 20-30%. We're only due to collide with rocks larger than one kilometre across roughly once every 600,000 years, it concludes." Whew! What a relief!"

13 of 231 comments (clear)

  1. More importantly... by ohad_l · · Score: 3, Interesting

    How likely are we to be able to nuke 'em once we see them? How likely are we to see those anyway? We've had several near-misses that we only detected after the asteroid passed us...

    --
    If it weren't for fog, the world would run at a really crappy framerate.
    1. Re:More importantly... by fname · · Score: 4, Interesting

      Depends on the advance warning. With 30-40 years notice, we'd probably have time to send out a scout team to characterize the asteroid. Then, we could send a follow on team with the proper explosives and nukes. Hit it soon enough (at least a couple years before collision), and we could deflect it.

      Some folks think that painting it is a better solution. You see, if you paint part of it white, it will deflect the asteroid by about 1 earth-radius 20 years ahead of time. (Less than the margin of error in our guess, most likely. Might knock it into us.) And, to paint a 100-meter or 1-kilometer rock takes A LOT of paint.

      Anyways, the short of it is, if it's an asteroid, we can probably have 100 years notice if it's big enough (not today, but our detection ability is improving). If it's a comet, we might only have a few months notice. Then we'd be in trouble.

    2. Re:More importantly... by barakn · · Score: 2, Interesting
      Would you regret learning something? I'll assume you live in the northern hemisphere and you've experimented with a top before. After you sped it up, and as long as it was spinning fast enough, the axis it spun around didn't change much. You never noticed it suddenly flip over and spin on its head, did you? The Earth's rotation acts the same way.

      The north pole of our axis of rotation is pointed at a spot in the universe known as the North Celestial Pole. There happens to be a star near that spot which has acquired the names of the North Star and Polaris. If you watched the stars all night, they'd all appear to rotate around this spot. This spot will always stay at the same altitude due North of you, unless you change latitude.

      There's also a South Celestial Pole, and if you could see through the earth you'd see that the stars below your feet wheel around the South Celestial Pole. No matter how long you watched, though, stars within a certain distance of that pole will never rotate far enough to get above your horizon. For example, most northerners have never seen the Large and Small Magellanic Clouds. I hadn't until I made a trip to South America. They're pretty strange looking.

      --
      "I'm so moist I'm sticking to the leather." -Kermit the Frog on The Late Late Show
    3. Re:More importantly... by wrmrxxx · · Score: 2, Interesting

      We are spinning and moving, but we are doing so around fixed axes: spinning around an axis from the north to south pole, and moving around an axis through the sun that is nearly parallel to the earth's rotational axis.

      Try drawing yourself a diagram (looking 'side on' to earth) complete with sight lines from a person on the surface of the planet to objects out in space. It will become fairly clear that the further north you go, the less of the universe that is to the south of the earth will be visible, because the earth itself blocks your view. There is effectively a cone of non visible space. The spinning motion gives the most comprehensive view of the universe to people on the equator: they get to see it all, but only over time as the earth spins.

      Many if not most of the names of stars are not Greek or Roman (as we might otherwise expect given the roots of our language), but Arabic. This is because the Arabs were further south and were able to see many more stars than the ancient Greeks or Romans. For example: Altair, Rigel, Betelgeuse, Fomalhaut, Aldebaran, Vega, and Algol are all names with Arabic origins.

  2. THIS made the front page of Slashdot? by Chromodromic · · Score: 5, Interesting
    This must just be an abysmally slow news-for-nerds day or something because, you know, the joke in the post is valid. Did anyone breathe a sigh of genuine relief here? Did anyone go, "Oh, God, well, now I can stop worrying about that!"

    Did anyone see Armageddon and then go home unable to sleep for nights on end?

    I just find it hard to believe that in the vast informational space of the Internet, this is a story that collided with the front page of Slashdot.

    The analysis doesn't change the chance of an asteroid hitting the Earth, points out astronomer Iwan Williams of Queen Mary University of London, UK. "But assuming that there are fewer large asteroids, the damage will be less," he says.

    When news editors say, "Damn it, just print something!", this is what we get.

    --
    Chr0m0Dr0m!C
  3. But is it a Poisson Process? by mattyp · · Score: 3, Interesting

    It makes a big difference. If it's a Poisson Process, no matter how long we wait, every day our probability of being struck remains the same. If not, every day that we don't get struck, increases our probability for getting struck the next day.

  4. down 20-30%...? by Devil's+BSD · · Score: 2, Interesting

    if we're going to be hit by a massive asteroid approximately every 600,000 years, doesn't that kind of make the probability 100%?

    --
    I'm the Devil the Windows users warned you about.
  5. I wouldn't worry by earthforce_1 · · Score: 2, Interesting


    We have plenty of more probable ways to destroy civilization. Assuming we do absolutely nothing about the problem for another 1000 years, the change of getting clobbered by "the big one" is still miniscule, and the odds are still much less that we won't detect it in enough time to do something. There have been a few near misses that were not detected until the last moment, but many others were found with decades of warning - enough time to devise a mission from scratch to push the sucker into a slightly different trajectory.

    And by that time I predict we will either be i) extinct, ii) living in a second stone age, or iii) have unimaginable technology such as planet wide deflector shields or some super weapon that could take care of the problem in the blink of an eye.

    --
    My rights don't need management.
    1. Re:I wouldn't worry by Saeger · · Score: 2, Interesting
      or iii) have unimaginable technology such as planet wide deflector shields

      With "unimaginable technology" why would you assume the majority of life will still be living in fragile bio-based bodies at the bottom of gravity wells with tons of wasted molecular building material beneath our feet?

      I say we rip the Earth apart to put it to better use - sentimental value be damned! :)

      --

      --
      Power to the Peaceful
  6. Just relax... by DruggedBunny · · Score: 2, Interesting

    Yeah, take it easy. Two major asteroids passed within 200,000 miles of us (less than the distance to the moon) in the last year or so... http://science.slashdot.org/article.pl?sid=02/01/0 7/138256&mode=thread&tid=160 http://science.slashdot.org/article.pl?sid=02/06/2 0/1916206&mode=thread&tid=160 Fortunately, we didn't know about them until after they had passed...

  7. System effects by Beryllium+Sphere(tm) · · Score: 4, Interesting

    You can calculate the energy release, overpressure radius, and so on. You can estimate the casualties and property damage from a half-kilometer disaster.

    My nightmare, though, is having the next Tunguska-sized event happen during the next Cuba-like nuclear crisis.

    It only takes a small rock to do a good short-term simulation of a nuclear weapon going off. If that happened at the wrong place and wrong time, it could trigger indescribable horror.

    1. Re:System effects by bugg · · Score: 2, Interesting

      I see you're an optimist. The world has come painfully close to nuclear war more than most people would care to know.

      --
      -bugg
  8. great, now all we have to worry about is... by mediaisthemassage · · Score: 2, Interesting
    the yellowstone caldera blowing its top....it's already "overdue"...

    see this national geographic article

    if this thing blows in our lifetimes, the midwest will essentially become Mordor...I guess for some hardcore LOTRs fans that would be kind o' cool...

    Then again, LOTR trilogy is hella better than any asteroid hitting the planet movie...