BY admin | February 16, 2013
(NVONews.Com) It is a case of double coincidences. Not only the meteor once again hit Siberia in Russia, but it plunged into the Ural Mountains the day when the asteroid missed the earth by 15 minutes.
Asteroid 2012 DA14, discovered just last year, passed about 17,200 miles (27,700 km) from Earth at 2.25 PM EST (1925 GMT), closer than the networks of television and weather satellites that ring the planet.
On the other hand the meteor that exploded over Chelyabinsk, Russia, at 10.20 PM EST on Thursday (0320 GMT Friday) came from a different direction and different speed than 2012 DA14.
NASA scientists said the two events, both rare, are not related. “It’s simply a coincidence,” Paul Chodas said during a webcast showing live images of the asteroid from a telescope in Australia. The US Congress has asked NASA to find and track all near-Earth objects that are 0.62 miles or one km in diameter or larger.
Sources said the effort is intended to give scientists and engineers as much time as possible to learn if an asteroid or comet is on a collision course with Earth, in hopes of sending up a spacecraft or taking other measures to avert catastrophe.
Scientists say that some 66 million years ago, an object 10 km in diameter smashed into what is now the Yucatan Peninsula in Mexico, leading to the demise of the dinosaurs, as well as most plant and animal life on Earth. They estimate that only about 10 per cent of smaller objects, such as 2012 DA14, have been found.
On the other hand Paul Dimotakis, a Professor of Aeronautics and Applied Physics at the California Institute of Technology in Pasadena was quoted in the media as saying: “Things that are that tiny are very hard to see. Their orbits are very close to that of the Earth.”
Astronomer Donald Yeomans, who is associated with NASA’s Jet Propulsion Laboratory in Pasadena, California, said the planet is regularly pelted with objects from space, adding up to about 100 tons of material per day.
He said rocks the size of basketballs come in every day. Things the size of a small car arrive every couple of weeks. Larger meteors are less common, so the frequency of hits decreases.
NASA said the rock that broke apart over Russia was believed to be a tiny asteroid, estimated to be about 49 feet and traveling at 11 miles (18 km) per second.
“These things are very faint until they get close enough to the Earth to be seen. An asteroid such as this, which approaches the Earth from the daytime sky, is virtually impossible to see ahead of time because telescopes have to look in the night-time sky to discover asteroids,” said Chodas.
As reported the Russian fireball was the largest space rock to hit Earth since the 1908 Tunguska event when an asteroid or comet exploded over Siberia, leveling 80 million trees over 830 square miles (2,150 sq km).
Asteroid 2012 DA14 blazed past the planet at about eight miles (13 km) per second. At that speed, an object of similar size on a collision course with Earth would strike with the force of about 2.4 million tons of dynamite, the equivalent of hundreds of Hiroshima-type bombs.
“It’s a good thing it’s not hitting us, because truth be told there’s nothing we could do about it except possibly evacuate, which is not going to be easy given the uncertainty about where the impact would take place,” Dimotakis said.