Astronomers have revealed that an asteroid capable of demolishing an entire city narrowly missed hitting the Earth on 14 June.

The 120 metre-long Asteroid 2002 MN passed the earth at a distance of 120,000km. In galactic terms, this is a tiny distance.

This is the first known time that an asteroid has come this close to Earth since December 1994, when a ten-metre rock came within 105,000km of the planet.

A spokesperson for the British-based Near Earth Object Information Centre said that this latest asteroid would have caused local damage similar to the devastation which occurred in Siberia in 1908 when 2000 square kilometres of forest were flattened by a space object.

The risk of an asteroid or comet hitting the earth is very remote. Very few objects come as close as 2002 MN did.

Astronomers are trying to map large asteroids, greater than a kilometre across, which could cause lasting climate change. One theory suggests that dinosaurs were wiped out by such an asteroid hitting what is now modern-day Mexico, 65m years ago.