Asteroid impact: 1908's Tunguska event is thought to have been caused by an asteroid that exploded before it hit the Earth's surface, taking out an estimated 80 million trees in a remote swath of Siberia.
Credit: NASA
PARIS: An asteroid of a similar size to a rock that exploded above Siberia in 1908 with the force of a thousand atomic bombs whizzed close past Earth this week, said astronomers.
2009 DD45, estimated to be between 21 and 47 m across, raced by at 13:44 GMT on Monday, the Planetary Society, based in Pasadena, California, and astronomers blogs reported.
"The space rock was discovered only two days ago by Rob McNaught at Siding Spring Observatory in Australia, when it was a dim speck about 1.5 million km away," said the Planetary Society web site on Monday.
Not much further than some satellites
"To give an idea of just how close a shave this was, consider this: 70,000 km is just one fifth of the distance from the Earth to the Moon, and only twice the distance at which geostationary telecommunications satellites orbit," the society said.
The estimated size of the object is similar to that of an asteroid or comet that exploded above Tunguska, Siberia, on June 30 1908, flattening 80 million trees in a swathe of more than 2,000 square kilometres.
2009 DD45 was spotted last Saturday by astronomers at the Siding Spring Observatory, and was verified by the International Astronomical Union's Minor Planet Centre (MPC), which catalogues Solar System rocks.
The closest flyby listed by the MPC is 2004 FU162, a small asteroid about six metres across which came within about 6,500 km of us in March 2004.
