A meteor strike in Russia and an asteroid near-miss graphically reveal the risks facing planet Earth. But we're not powerless.
Spaceship Earth just took two celestial shots across its bow as, first, a meteor struck Russia, showering the Chelyabinsk region with fragments and reportedly injuring several hundred people, and second, as Asteroid 2012 DA14 whizzed past on 15 February. Traditionally, a torpedo across the bow is fired as a warning to change one's behavior – and this coincidence of events should be a warning to humanity that meteors are not always as benign as "shooting stars" and that the next asteroid might not miss! Will we, the crew of SS Earth heed this warning?
On 15 February 2013 a meteor exploded over Siberia and an asteroid is expected to pass 17,100 miles above the earth. Photograph: Getty Images.
We can look at asteroid 2012 DA14 (or DA14 for short), which will have missed the Earth by a mere 17,000 miles, in two ways. DA14 can be seen as one of about 10,000 near-Earth asteroids that have been discovered in the past 15 years that pass close to our planet, threatening an impact. However, since we have seen these asteroids and are currently tracking them, we can predict any upcoming impacts. Happily, none of those we've found to date pose any substantial threat of impact.
Nevertheless, the Earth is hit by one of these relatively small DA14-sized asteroids about once every 300 years, on average. And "small" is far, far from insignificant. The DA14-like asteroid that hit Earth in 1908 did so in a remote region of Siberia, where the explosion (the equivalent of about 250 Hiroshima nuclear bombs going off at one time) destroyed over 800 square miles of the countryside. This disaster zone, superimposed on any city in the world, would have wiped it and all its residents from the face of the Earth. I refer you, as a graphic reminder of the power of such explosions, to the post-facto Hiroshima bomb pictures readily found online.
Source : guardian , UK ( 15th feb 2013)
Spaceship Earth just took two celestial shots across its bow as, first, a meteor struck Russia, showering the Chelyabinsk region with fragments and reportedly injuring several hundred people, and second, as Asteroid 2012 DA14 whizzed past on 15 February. Traditionally, a torpedo across the bow is fired as a warning to change one's behavior – and this coincidence of events should be a warning to humanity that meteors are not always as benign as "shooting stars" and that the next asteroid might not miss! Will we, the crew of SS Earth heed this warning?
On 15 February 2013 a meteor exploded over Siberia and an asteroid is expected to pass 17,100 miles above the earth. Photograph: Getty Images.
We can look at asteroid 2012 DA14 (or DA14 for short), which will have missed the Earth by a mere 17,000 miles, in two ways. DA14 can be seen as one of about 10,000 near-Earth asteroids that have been discovered in the past 15 years that pass close to our planet, threatening an impact. However, since we have seen these asteroids and are currently tracking them, we can predict any upcoming impacts. Happily, none of those we've found to date pose any substantial threat of impact.
Nevertheless, the Earth is hit by one of these relatively small DA14-sized asteroids about once every 300 years, on average. And "small" is far, far from insignificant. The DA14-like asteroid that hit Earth in 1908 did so in a remote region of Siberia, where the explosion (the equivalent of about 250 Hiroshima nuclear bombs going off at one time) destroyed over 800 square miles of the countryside. This disaster zone, superimposed on any city in the world, would have wiped it and all its residents from the face of the Earth. I refer you, as a graphic reminder of the power of such explosions, to the post-facto Hiroshima bomb pictures readily found online.
Source : guardian , UK ( 15th feb 2013)
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