Asteroid 2004 XP14 will pass Earth at a mere distance of 1.1 times the distance between the Earth and the Moon at 05:25 BST on Monday 3 July. According to NASA�s Jet Propulsion Laboratory (JPL), the asteroid is somewhere between 370 and 820 metres across.

"It's not Earth-threatening," said Don Yeomans, of NASA's Near Earth Object Program. "For something of this size to come this close is unusual."

Whilst the miss distance of around 432 308 kilometres is close in astronomical terms, astronomers have ruled out any possibility of it colliding with the Earth on Monday, or at any time in the next century. 2004 XP14 will make another close approach in 2019, and again in 2020, although neither will be as close as Monday�s pass.

The asteroid will pass through the constellations Perseus, Cassiopeia, Cepheus and Draco. It will have an apparent magnitude of +12 so it will only be visible with large telescopes.

2004 XP14 was spotted as part of the Lincoln Near-Earth Asteroid Research (LINEAR) project, with a telescope based in New Mexico, USA, in December 2004.