Scientists bid to land probe on asteroid

Space exploration is taking a step forward with the attempt to land a probe on an asteroid.

If all goes according to plan, the spacecraft will drop on to the surface of the 21-mile long sausage-shaped rock just after 8pm on Monday, UK time.

The American space agency Nasa's Near Shoemaker probe has been orbiting the asteroid 433 Eros for a year and controllers are now ready to attempt the first landing on one.

At present, Eros - the second largest "near-Earth" asteroid - is more than 196 million miles away.

The main goal of the descent is to gather close-up pictures of the asteroid's boulder-strewn surface.

A secondary aim is to practise manoeuvres that might assist similar future missions.

Information from Eros could help scientists if a large asteroid is spotted heading towards the Earth.

During its five-year, two billion mile journey, Near (Near Earth Asteroid Rendezvous) provided the most detailed information obtained yet on a small celestial body.

It began orbiting Eros on February 14 last year, and has collected 10 times more data than originally planned. About 160,000 images showed the asteroid's surface to be covered in boulders, craters and dust.

Near project scientist Dr Andrew Cheng, of the Applied Physics Laboratory at Johns Hopkins University in Baltimore, said: "We have answered the questions we had when the orbit began. We now know that Eros is a solid body of uniform composition, made of material probably older than the Earth.

"But we also found many other things we didn't expect to see and have questions we didn't know to ask at the start of the mission. Scientists will be looking at these data for years."