Earth-approaching space rock found by accident

The space rock tracks across this 400 second exposure

By BBC News Online science editor Dr David Whitehouse

A new member of the family of asteroids that can pass close to the Earth has been discovered.

The space rock was found by accident on 2 July by astronomer Leonard Amburgey of Fitchburg, Massachusetts.

He typed in the wrong celestial co-ordinates into his computer-controlled telescope and stumbled across the 3-km (1.8 miles) sized object.

The asteroid has been given the temporary designation 2000 NM by the Minor Planet Center in Cambridge, Massachusetts. It poses no threat to Earth.

Astronomers say this is the brightest near-Earth asteroid to be discovered in the past year.

Professional miss

However, they are concerned that it was found by accident and was missed by the half dozen professional minor-planet surveys currently in operation.

At the moment, it is about 22 million km (13 million miles) from Earth. It crosses inside the Earth's orbit at the end of July, on its way to its closest approach to the Sun in late August.

Since the asteroid's discovery, a variety of telescopes from around the world have been collecting data on it.

Astronomers hope that by looking for variations in its brightness they may get some idea of how fast the space rock is spinning.

An accurate estimation of its orbit would also help them determine if it is likely to pass close to the Earth in the future. A collision, however, has been ruled out.