Asteroid to ram Earth

In February, Earth was almost placed on impact alert because of an asteroid then thought to be on an impact course. Mr Schweickart told a hearing that "the media and the general public realise that asteroids are of more than passing interest."

An unmanned spacecraft should test ways to deflect a threatening asteroid, two astronauts have told the US government. Rusty Schweickart and Edward Lu said a mission of this type could be launched to an asteroid in 2015.

Testifying before an investigation into the threat from asteroids to the Earth, Apollo astronaut Russell L Schweickart called for a new mission to develop the technologies needed to protect the Earth. "More and more people are coming to know that some few of these asteroids do not silently pass the Earth, but indeed crash in, largely unannounced.

He pointed out that even the small, most frequent events are more powerful than the blast from the most powerful nuclear weapon in the current US nuclear arsenal.

"A known threat that can potentially destroy millions of lives and can be predicted to occur ahead of time, and prevented, cannot responsibly go unaddressed," he said, report BBC.

According to freep.com thousands of space rocks 300 feet in diameter and larger hurtle through erratic orbits in the Earth's space neighborhood, former astronaut Russell Schweickart told a Senate subcommittee.

If such a rock crashed into the atmosphere, it would explode at an altitude of 10,000 or 20,000 feet with the force of a 100-megaton nuclear weapon, he said.

Such a blast could destroy metro Detroit. It is only a matter of time before such an asteroid collides with the planet unless something is done to prevent it, Schweickart and others testified.

With enough warning - perhaps a decade - astronauts could go to an asteroid that is projected to crash into the Earth, attach rockets to it and accelerate or decelerate it into a safe orbit, Schweickart said.

But without a sufficient space survey and demonstrated intervention technology, the Earth could be a sitting duck for a catastrophe, he said.

Following are parts of the testimony presented by astronauts Rusty Schweickart and Ed Lu before the U.S. Senate Subcommittee on Science, Technology, and Space at a hearing April 7, 2004. Schweickart was one of the Apollo astronauts, and Lu recently returned to Earth after a 6-month tour of duty on the International Space Station. Their discussions deal primarily with a proposed demonstration mission to develop technology for deflecting an asteroid.

Others testifying at the same hearing include Wayne Van Citters, Director of the Division of Astronomical Sciences, National Science Foundation; Lindley Johnson, Program Manager of the NASA NEO Observation Program; Grant Stokes, Associate Head of the Aerospace Division of the MIT Lincoln Laboratory and chair of the recent NASA Science Definition Team on sub-km NEOs; and Michael Griffin, Head of the Space Department of the John Hopkins University Applied Physics Lab, inform spaceref.com