Asteroid misses Earth by 4 hours

By CAHAL MILMO

LONDON - In intergalactic terms, it was a close shave. An asteroid capable of causing widespread devastation narrowly missed the Earth yesterday.

Although the nearest the asteroid came to Earth was 627,000km, had it arrived four hours earlier on its journey around the Sun it would have scored a direct hit.

When the asteroid - measuring 300m across and known as 2001 YB5 - passed Earth it was less than twice as far from the Earth as is the Moon.

Scientists were unaware of its approach until a month ago, when it was spotted by an American observatory dedicated to tracking near Earth objects (NEOs).

Astronomers insisted there was never any danger of a collision with Earth. But they warned that the asteroid was one of up to 400,000 small NEOs up to 1000m wide that could strike Earth with little or no warning because of the absence of an adequate early warning system.

The idea of a catastrophic asteroid strike has long been a source of morbid fascination, most recently manifesting itself in Hollywood disaster movies such as Armageddon and Deep Impact.

The potential consequences are indeed apocalyptic, according to research on asteroid impacts. If a 300m asteroid hit London, it would destroy everything within a 150km radius and cause severe damage for a further 800km - wiping out the United Kingdom, the Low Countries and much of France.

In the more likely event of a similarly sized NEO landing in the sea (70 per cent of the Earth's surface is covered by water), it would trigger a series of tsunamis that would devastate coastal regions.

Jonathan Tate, director of Spaceguard UK, which campaigns for a British-funded telescope to watch for such asteroids as part of a global network, said: "YB5 is one of hundreds of thousands of objects which present an unknown risk to the planet.

"What limited resources exist for tracking asteroids are dedicated to spotting the 700 to 1200 which are more than a kilometre in diameter and, if they hit the Earth, could wipe out the planet.

"That leaves very few resources for trying to trace the many more asteroids between 100m and 1000m in diameter which still present a very significant risk.

"This particular asteroid passed us by without any danger but it remains that by the time it was spotted last month, there was nothing we could have done to avert a catastrophe."

- INDEPENDENT