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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!"

15 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. Re:Okay, so we don't have to worry... by fuctape · · Score: 1, Interesting

    We don't have to worry about it from a statistical point of view (case in point: the Doomsday Problem), but if there's a pattern of life-threatening impacts historically, we might want pay attention. IIRC, there's a cycle of 26 million years for extinction level impacts, give or take 10,000 years, and we *are*, in fact, overdue.

    The truth is that we won't be able to predict the one that will hit us -- you can track a fly ball, but the line drive to the face (with a lump of charcoal in the dark of night) becomes a problem.

  8. 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
  9. 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...

  10. Cosmic Cannon: Exploding Star Could Fry Earth by Anonymous Coward · · Score: 1, Interesting

    http://solar-center.stanford.edu/sun-on-earth/glob -warm.html
    1991 - "Global warming -- ...However, some solar scientists are considering whether the warming exists at all. And, if it does, might it be caused, wholely or in part, by a periodic but small increase in the Sun's energy output. An increase of just 0.2% in the solar output could have the same affect as doubling the carbon dioxide in the Earth's atmosphere."

    http://www.space.com/scienceastronomy/topmysteri es _2003_021226-7.html
    Top 10 Space Mysteries for 2003
    7. The Enigmatic Sun
    If you're looking for a career with a really bright future, become a solar physicist. Amazingly, we still don't fully understand the dynamics of the star we orbit.

    http://www.gsfc.nasa.gov/topstory/20010801solarp ro ton.html
    Stormy Space Weather Takes a Toll on Ozone
    Goddard Space Flight Center, August 1, 2001
    "A new study confirms a long-held theory that large solar storms rain electrically charged particles down on Earth's atmosphere and deplete the upper-level ozone for weeks to months thereafter.

    http://spacescience.com/headlines/y2000/ast22dec _1 .htm
    Watching the Angry Sun - Solar physicists are enjoying their best-ever look at a Solar Maximum thanks to NOAA and NASA satellites, NASA Press Release, December 22, 2000
    "This is a unique solar maximum in history," said Dr. George Withbroe, Science Director for NASA's Sun-Earth Connection Program. "The images and data are beyond the wildest expectations of the astronomers of a generation ago."

    http://www.space.com/scienceastronomy/astronomy/ ga mmaray_bursts_010522-1.html
    Cosmic Cannon: How an Exploding Star Could Fry Earth
    19 June 2001
    "While scientists have long tried to link supernovae to mass extinctions on Earth, there is no solid evidence. But recent observations of high-energy emissions in space have some scientists suggesting that our planet may in fact get fried every now and then."

    http://www.gsfc.nasa.gov/topstory/20011120sohoga s. html
    SOHO'S LATEST SURPRISE: GAS NEAR THE SUN HEADING THE WRONG WAY
    Goddard Space Flight Center, November 20, 2001
    "We are seeing something opposite to what we expected," says Sheeley. "Normally, when this happens, we initially doubt the observation -- suspecting, for example, that the movie is running backwards."

    http://abcnews.go.com/sections/scitech/DailyNews /m ars011207.html
    Red Planet Warming, Images Show Mars' Ice Caps Are Melting Fast
    Dec. 7, 2001
    "We weren't expecting to see something nearly this large," said Caplinger.

    http://www.gsfc.nasa.gov/topstory/2003/0313irrad ia nce.html
    NASA STUDY FINDS INCREASING SOLAR TREND THAT CAN CHANGE CLIMATE
    March 20, 2003
    Since the late 1970s, the amount of solar radiation the sun emits, during times of quiet sunspot activity, has increased by nearly .05 percent per decade, according to a NASA funded study.
    "This trend is important because, if sustained over many decades, it could cause significant climate change," said Richard Willson, a researcher affiliated with NASA's Goddard Institute for Space Studies and Columbia University's Earth Institute, New York.