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Short notice for asteroids’ near-miss

Tunguska260.jpg The announcement from NASA yesterday that two small asteroids would today miss our planet by less than the distance between the Earth and the Moon brings into focus the short notice that we are likely to have of any collision from smaller space rocks.

One asteroid, 2010 RX30, estimated by NASA to be between 10 and 20 metres across, passed within 248,000 kilometres of Earth at 10.51 am BST today. The second, 2010 RF12, estimated to be only 6 to 14 metres across, will pass within 79,000 kilometres at 10:12 pm tonight. Both were only discovered on Sunday, just three days before their time of closest approach. That is due to their small size; smaller objects are harder for telescopes to pick up.

It’s unknown exactly how much damage such objects would do if they did hit Earth. In 2008, Mark Boslough and David Crawford of Sandia National Laboratories published simulations showing that a 30 to 50 metre asteroid could cause substantial damage to Earth’s surface by depositing energy several kilometers up in the atmosphere, and causing a jet of expanding gas to plunge to the ground.


U.S. policy on hazardous asteroids is largely determined by the 2005 mandate to NASA, in the George E. Brown Jr. Near-Earth Object Survey Act, to detect and track 90% of Near-Earth Objects over 140 metres in size by 2020. As I report in a story this week on the NASA Ad-Hoc Task Force on Planetary Defense, NASA is unlikely to meet the goal, but is detecting many smaller objects because of it, some of which are likely to have initial probabilities of hitting Earth. During their deliberations, panel members noted that the agency ought to keep track of objects smaller than 140 metres when they are detected – although not if this comes at the expense of tracking the larger ones.

Image: Devastation at Tunguska in Russia in 1908 is now thought to have been caused by a 30-50 metre asteroid / Leonid Kulik Expedition

Comments

  1. Report this comment

    Douglas Gilbert said:

    NASA who allowed its moon program to be canceled without protest is telling us to not worry. They say that now their main goal is to promote scientific pride in the minds of certain inhabitants of third world countries. A noble cause I suppose. I can’t be any more polite than this. And a certain amount of sarcasm is necessary who those who have been keeping up with the news and know what I mean.

         If a large meteor were to approach Earth, would anyone tell us? I say enough with the Government’s panic-phobia. Just let us panic for a change. We might enjoy it, and maybe we would fund NASA again and have a real space program once more…

  2. Report this comment

    Simon said:

    Love the comment from Douglas Gilbert about enjoying a good panic 🙂 – might even provide some economic stimulus – ie people out buying survival gear or spending money like there’s no tomorrow.

    just read an excellent book called “Lucifers Hammer” which describes a newly discovered comet hitting earth.

  3. Report this comment

    Peter Blau said:

    As I sadly watch NASA’s mystique fade into history, I feel truly fortunate to have had the chance to study the Apollo lunar samples in graduate school during the early 1970s. It may be impossible to recapture the excitement of those heady days,an excitement that transcended the kind of social division and political nonsense that plague today’s America.

  4. Report this comment

    Mark Hayes said:

    If you plug the parameters and likely impact characteristics of the larger of the 2 near misses into the Earth Impact Effects Program (http://impact.ese.ic.ac.uk/ImpactEffects/) you will see that such an asteroid is fairly common, will break up into fragments before impact and will have little effect on anyone(unless a chunk of it hits you on the head). Now maybe the estimates aren’t accurate, but these near misses don’t seem like something to get excited about.

  5. Report this comment

    Douglas Gilbert said:

    Peter Blau,

         Thank you for your comment. I’m glad you got the gist of what I was saying despite my typo(who—>for).

         If we had a moon base, perhaps asteroid and meteor tracking and interception would be more feasible.

  6. Report this comment

    Douglas Gilbert said:

    Simon,

    Thank you. I think a real space program would provide a lot of economic stimulus and scientific spin-offs. There appear to be few benefits from the space station. Although the Hubble Space Telescope has been a great success.

  7. Report this comment

    Douglas Gilbert said:

    According to NASA panel weighs asteroid danger , to “log 90% of the estimated 20,000 NEOs larger than 140 metres in diameter by 2020” is impossible and counter-productive. But a 30 meter one is a significant problem. But, overall, we will be tracking too many(even of significant size) unlikely to hit. Survey telescope near Venus:problematic. Large Synoptic Survey Telescope (LSST) on Cerro Pachón in Chile: problems. Seems with any plan at present, a large lucky asteroid hitting Earth undetected until too late is likely to happen in the next __(?) years. Clueless? or not?

  8. Report this comment

    asamoah said:

    It,s all good for man to seek knowledge in all facets of life but if resouces become scarce and basic human needs can not be met adequetely mere common sense must be applied.Rethink your priorities.Life is not a trafic, when is red all moving things in that direction must stop.In life everything affects everything and everything is in motion.Danm Politics.

  9. Report this comment

    Linden Method said:

    If a large meteor were to approach Earth, would anyone tell us? I say enough with the Government’s panic-phobia. Just let us panic for a change. We might enjoy it, and maybe we would fund NASA again and have a real space program once more.

Comments are closed.