400-metre asteroid to miss Earth by a cosmic whisker
Published 09/11/2011 | 05:00
An asteroid bigger than the Empire State Building will pass by Earth tonight at a distance closer than the moon, NASA said yesterday. It is the largest object in more than three decades to fly so near.
The spherical rocky object, 400 metres in diametre, is the largest asteroid to come this close since 1976.
At 11.28pm Irish time, the asteroid, dubbed 2005 YU55, will be about 201,700 miles from Earth, or about 0.85 times the distance from the moon to the planet. No discernible effect on the gravitational field will be felt, according to NASA.
The asteroid is one of more than 8,500 near-Earth objects to be cataloged. At a quarter of a mile long, it is larger than the iconic New York building, which is 1,250 feet tall.
Although the asteroid will be too faint to see without a telescope, scientists will be studying its composition closely in order to gain clues about the formation of the solar system.
While experts say there is no danger of the object hitting the planet, if it were to veer off course, 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.
Nasa has set up its Near Earth Object Programme, known as 'Spaceguard', to track potentially hazardous space objects.
By the end of the decade, it aims to locate at least 90pc of an estimated 1,000 asteroids and comets larger than one kilometre in diameter. Objects of this size are big enough to cause the extinction of most life on Earth.