Earth set for close encounter with asteroid

The 1,300ft wide asteroid, 2005 YU55, will miss the Earth by 201,700 miles – a comfortably safe margin despite being no distance in astronomical terms.

Amateur astronomers with suitable equipment may be able to spot the object, though it will be hard to see. Scientists will track the asteroid’s fly-by by radar using ground-based antennae in California and Puerto Rico.

If 2005 YU55 hit the Earth it would unleash a 4,000-megaton blast.

The impact could wipe out a city the size of London or New York, while landing in the sea would cause a 70ft high tsunami.

But experts stress there is no chance of such a disaster happening because the asteroid’s trajectory is well understood.

According to their calculations, the rock will approach to 0.85 the distance of the Moon from the Earth at 10.28pm UK time tomorrow. It will be the closest the space rock has come to the Earth in at least 200 years.

Dr Robert Massey, of the Royal Astronomical Society, said: “It is an unusually large object for one making a close approach. But the distance between us and the asteroid is still many times the diameter of the Earth, so it doesn’t present any risk to us at all. There really is nothing to worry about.”