A close encounter

Asteroid's Earth fly-by will enter satellite zone

An asteroid half the size of a US football field will dart between Earth and orbiting satellites next week, sparing the human race and putting on a show for sky gazers in Eastern Europe, Asia and Australia, NASA said.

SMH,

8 February, 2013

The 150-foot diameter asteroid, named 2012 DA14, will pass 27,358 kilometres above Earth on February 15 -- lower than the orbits of some satellites -- in the closest known approach of an object of its size. It will travel on a north-to-south trajectory at 7.8 kilometres a second, or about eight times the speed of a rifle shot, NASA scientists said today.

"No Earth impact is possible," Donald Yeomans, who manages the Near-Earth-Object office at Pasadena, California- based Jet Propulsion Laboratory, said Thursday.

The NASA unit monitors relatively small space objects such as DA14 to measure the risks they present to the Earth. Researchers said the asteroid's close trajectory will help NASA in preparing for an eventual encounter with a near-Earth object later this decade.

While a strike by an asteroid DA14's size would do "a lot of regional destruction," it wouldn't be catastrophic to the planet's population, said Lindley Johnson, program executive for NASA's Near-Earth Object observations program in Washington.

Mr Yeomans said the damage from DA14 if it were to hit would rival an impact event in Russia in 1908 that levelled trees over an 820-square-mile territory. The asteroid that is thought to have wiped out the dinosaurs was about 10-kilometres in diameter.

Space Station Safe

The NASA scientists said the asteroid would still pass above the orbits of most of the communications satellites circling Earth, and doesn't pose a threat to the International Space Station, which moves above the planet at about 250 miles.

Amateur astronomers will need a small telescope to see the asteroid, which would appear as a moving pinpoint in the night sky, said Timothy Spahr, the director of the Minor Planet Centre in Cambridge, Massachusetts. The best viewing location for DA14's closest approach is Indonesia, with sky gazers in Eastern Europe, Australia and Asia also getting good looks at the asteroid.

The NEO program office said that an object of similar size gets this close to Earth once every 40 years, and that an actual collision can be expected only once in 1200 years.

Some companies and entrepreneurs are eying asteroids as possible sources for trillions of dollars in precious metals.

Planetary Resources Inc., based in Seattle and backed by Google Inc. Chief Executive Officer Larry Page and Chairman Eric Schmidt, are working to launch a telescopic space surveyor to identify resource-rich space rocks in the next couple of years.