Space watch for Earth-bound asteroids

The Government is expected to approve construction of a £10m telescope early in the New Year which would be dedicated to finding comets and asteroids before they hit Earth.

The Government is expected to approve construction of a £10m telescope early in the New Year which would be dedicated to finding comets and asteroids before they hit Earth.

The Science minister, Lord Sainsbury, is expected to accept one of the main proposals in a Government task force report - to develop a telescope with European partners to track "near-Earth objects" that could threaten the planet.

Scientists from the Government's expert team are now urging it to begin devising ways to deflect the objects when they have been identified.

Their report suggested detonating a nuclear bomb in space to deflect asteroids, using space craft to nudge objects out of their orbits, or erecting solar panels like sails on an asteroid, using the sun's radiation pressure to change its course.

The ideas may sound like the script from the Hollywood blockbuster Deep Impact which is to be screened on BBC1 on Tuesday. However, the scientists warned: "This is not science fiction."

An asteroid travelling at more than 20 miles per second missed the Earth by 480,000 miles last week, a near-miss in astronomical terms. The 50-yard wide asteroid, called 2000 YA, appeared unexpectedly above London at midnight on Friday. Space experts said it would have left a crater about 20 times its size if it had struck.

Massive asteroid and comet strikes on Earth have been well documented, including one 50 yards across which exploded 15 miles above Siberia in 1908. A comet hitting the Gulf of Mexico 65 million years ago is thought to caused the extinction of the dinosaurs.

Nasa will launch its own Deep Impact mission to the comet Tempel 1 in 2004. The probe will release a half ton lump of pure copper to cause a huge crater in the comet so that its composition can be studied from Earth.

The threat posed by the Mir Russian space station as it falls to Earth next week has also highlighted the real risks from impacts of objects from space.

Harry Atkinson, the chairman of the Government task force on "near-Earth objects," said: "We hope all our recommendations will be taken up but the telescope is the important one. We need to know where the objects are coming from. That is the high priority. It needs to be dedicated, working all the time."

Dr Atkinson said his three-man team began as sceptics but became more convinced of the need for action as they investigated the threat.

A telescope to hunt for objects in outer space on a path to Earth could be established in co-operation with European partners in the inter-governmental European southern observatory in Chile, which Britain has recently joined.

While the chances of a direct hit on Britain are remote, an object only 50 yards across hitting the mid-Atlantic would set up a shock wave which would cause devastation on the shores of the Continent, Britain and the eastern seaboard of the US.

Lembit Opik, the Liberal Democrat MP who led the successful Parliamentary campaign to persuade the Government to take the outer-space threat seriously, said a "sheath in space" or "cosmic condom" could be the best way of deflecting asteroids or comets comprising rocks and gas.

"You could have a big plastic cosmic condom or space sheath to collect near-Earth objects and tow them away to safety," he said.