Earth set for close encounter with asteroid

A Halloween asteroid the size of four football pitches is due to miss the Earth by just 300,000 miles on Saturday. By astronomical standards, that is frightfully close.

But scientists say there is no need to be scared, even on Halloween.

The 400m-wide space rock, travelling at around 22 miles per second, will remain further away than the moon.

There is no chance of the asteroid hitting the Earth for the next 100 years at least, and it is not included in the European Space Agency’s official list of potentially threatening near earth objects (NEOs).

But even so, Dr Detlef Koschny, who heads the agency’s NEO tracking team, said: “The fact that such a large near-Earth object capable of doing significant damage if it were to strike our planet was discovered only 21 days before closest approach demonstrates the necessity for keeping daily watch of the night sky.”

The asteroid was spotted by astronomers in Hawaii on October 10. It is due to fly past the Earth at around 5pm, Irish time, on Saturday.

Dr Marco Micheli, an astronomer from the European Space Agency’s NEO Co-ordination Centre in Italy, said: “The diameter of about 400m has a large uncertainty, as is usual in cases of any object for which we do not yet know details, such as its composition.”

He said more accurate information will be obtained once the object has been tracked by radar.