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A Tunguska Reminder

Universe Today offers up the latest edition of the Carnival of Space while announcing it will become the new venue for this gathering of Web links on space-related subjects. Among the posts garnered this time, it’s Universe Today‘s own take on the Tunguska event that should most resonate with Centauri Dreams readers. Tadeusz J. Jopek (Astronomical Observatory UAM in Poland) and team have run simulations of the 1908 explosion to estimate the velocity and impact angle of the Tunguska meteorite.

“We believe that TCB originated as the result of a breakup of a single body: a comet or an asteroid. In our study we concluded that it is more probable that it was an asteroid. We cannot point to which one; instead we have found several candidates for the Tunguska parent, and the asteroid 2000 WK63 is an example of it,” Dr. Tadeusz said.

Interesting! The relevant question, of course, is just how often we can expect such impacts to occur. Tunguska was, happily, a largely unsettled place at the time of the explosion, but what such a strike could do in a well populated area is horrific to contemplate. Thus the continuing significance of healthy planetary radar systems like Arecibo, whose funding troubles will stay on our radar until resolved.

Comments on this entry are closed.

  • Adam November 2, 2007, 22:23

    Hi Paul

    Tunguska was probably a stony meteorite since they have the lowest mechanical strength and are more likely to produce an air-burst.

    There was also the smaller Sikhote-Alin meteorite of 1947 which was a low-strength iron mass that broke-up before impact, and dug a few craters…

    http://en.wikipedia.org/wiki/Sikhote-Alin_Meteorite

    …smaller than Tunguska, which might have left a crater according to a paper back in August this year…

    http://www.blackwell-synergy.com/doi/full/10.1111/j.1365-3121.2007.00742.x?cookieSet=1

    …a free full-article from Blackwell-Synergy’s “Terra Nova” journal.

    Personally I wonder what it was that broke-up so catastrophically over North America 13,000 years ago. If the Carolina Bays are impact craters the impactor seems more like a spread of impactors – much like the rubble field that some comets have been observed to be.

  • ljk November 9, 2007, 10:48

    NASA pressed to avert catastrophic Deep Impact

    PhysOrg.com Nov. 8, 2007

    *************************

    NASA penny-pinching risks exposing
    humankind to a planetary catastrophe
    if a big enough asteroid evades
    detection and slams into Earth, US
    lawmakers warned…

    http://www.kurzweilai.net/email/newsRedirect.html?newsID=7464&m=25748

  • ljk December 19, 2007, 10:56

    SANDIA SUPERCOMPUTERS OFFER NEW EXPLANATION OF
    TUNGUSKA DISASTER

    Sandia national Laboratories, 17 December 2007

    ALBUQUERQUE, N.M. – The stunning amount of forest
    devastation at Tunguska a century ago in Siberia may
    have been caused by an asteroid only a fraction as large
    as previously published estimates, Sandia National
    Laboratories supercomputer simulations suggest.

    “The asteroid that caused the extensive damage was much
    smaller than we had thought,” says Sandia principal investigator
    Mark Boslough of the impact that occurred June 30, 1908.

    “That such a small object can do this kind of destruction
    suggests that smaller asteroids are something to consider.
    Their smaller size indicates such collisions are not as
    improbable as we had believed.”

    Because smaller asteroids approach Earth statistically
    more frequently than larger ones, he says, “We should be
    making more efforts at detecting the smaller ones than we
    have till now.”

    Full article here:

    http://www.sandia.gov/news/resources/releases/2007/asteroid.html

  • ljk March 9, 2008, 22:39

    The Tunguska Meteorite As A Warning From Outer Space

    File image of trees knocked down by the Tunguska impact.

    by Alexander Bagrov

    Moscow (RIA Novosti) Mar 09, 2008

    Almost a century ago, on June 17 (30), 1908, a massive explosion occurred near the Podkamennaya Tunguska River, in what is now Russia’s Krasnoyarsk Territory, Central Siberia.

    The residents of the Vanavara trading post, 65 kilometers (40 miles) south of the blast site, later claimed that the ground trembled violently when attacked by a huge ball of fire, followed by a terrible storm that destroyed everything in its wake.

    The explosion was most likely caused by the airburst of a large meteoroid or comet fragment at an altitude of 5-10 kilometers (3-6 miles) from the Earth’s surface. Studies have yielded varying estimates for the object’s size, with most experts agreeing that it measured several dozen meters in diameter.

    Estimates of the energy of the blast range from 5 megatons to as high as 30 megatons of TNT, with 10-15 megatons being the most likely yield. The blast, about 1,000 times more powerful than the Hiroshima bomb, felled an estimated 80 million trees over 2,150 square kilkometers (830 square miles). The earthquake caused by the blast measured 5.0 on the Richter scale. The region has never completely recovered.

    Full article here:

    http://www.spacedaily.com/reports/The_Tunguska_Meteorite_As_A_Warning_From_Outer_Space_999.html