The bus-sized asteroid that nearly hit earth!

An asteroid the size of a tour bus zipped past the Earth in a flyby so close that it was nearer to the planet than some satellites, National Aeronautics and Space Administration scientists have said.

The space rock, called asteroid 2011 MD, reached its closest point to Earth just after 17:00 GMT on June 27, when it crept within 12,000 km of the planet before whipping away again like a slingshot.

The asteroid, which was discovered on June 22, was flying over the southern Atlantic Ocean off the coast of Antarctica at the time of its closest approach. But, there was never any risk of it impacting earth, the scientists said.

"The asteroid was flying over the southern Atlantic Ocean, off the coast of Antarctica, at the time of its closest approach," space.com reported. The asteroid belonged to those rather diminutive group of space rocks, and no harm was predicted by astronomers even as it closed in on Earth ominously.

Asteroids this size can be expected to buzz Earth with close shaves about once every six years, they added. The space rock flew well below geosynchronous satellites, which orbit 22,236 miles (35,786 km) above Earth, but well above the 220-mile (354-km) altitude of the International Space Station.

There was little chance the asteroid would hit a satellite because of the vastness of space and the relatively small number of satellites, experts said. Don Yeomans, of NASA's Near-Earth Object Program Office in California, said that astronomers hoped to take radar observations 2011 MD during the asteroid's flyby.

However, hopes were low for any detailed images because of the space rock's small size, Yeomans added. Asteroid 2011 MD is the second space rock to zip extremely close by Earth this year. In February, asteroid 2011 CQ1 passed within 5,471km of Earth.