Asteroid mission extended

Scientists will continue to monitor signals from Near

Nasa is still receiving signals from the first spacecraft to land on an asteroid and has extended the mission by 10 days to gather important scientific information.

The secret of success here is that we did our homework several times

Bobby Williams, Nasa

Scientists hope the data from Near (Near Earth Asteroid Rendezvous) Shoemaker, which landed on Eros on Monday, will help them understand the relationship between space rocks like Eros and meteorites that have fallen to Earth.

Dr Jay Bergstralh of the American Space Agency Nasa, said on Wednesday: "We will extend the operation by 10 days to gather further data on the abundances of elements on the asteroid."

At a post-landing press briefing at Nasa's headquarters in Washington DC, the mission team revealed details of how they landed the craft.

'Success'

"The secret of success here is that we did our homework several times," said Dr Bobby Williams of Nasa's Jet Propulsion Laboratory, Pasadena, California.

"For a spacecraft that is not built to land this came off extraordinarily well."

More than 60 images were taken by Near Shoemaker craft on its descent.

Near Shoemaker's camera showed clear surface detail

The pictures show boulders strewn across the surface of Eros, some of them twice the size of Near, others only the size of a golf ball.

While they give clues to the make-up of the asteroid, they also raise further mysteries.

"Some of the big questions have been answered but fortunately many mysteries remain," said Joseph Veverka, Imaging Team Leader, Cornell University, Ithaca, New York.

"That is the whole point of exploration and discovery."

Faster, cheaper, better

The touchdown ended a five-year journey by the craft, one of the first of Nasa's "faster, better, cheaper" missions.

It was a remarkable feat for a probe that was only designed to orbit, rather than land. And, against all odds, Near is still transmitting signals to mission control.

Scientists believe that the signals could continue for the next few weeks until the Sun, which powers the craft's solar panels, moves out of range.

Near Shoemaker's landing point

Before the touchdown, Near had already orbited Eros for a year, sending back some 160,000 images of the rocky surface.

Asteroids, material left over from the formation of the Solar System, are rocky and metallic objects that orbit the Sun but are too small to be considered planets.

Because asteroids are material from the very early Solar System, scientists are interested in their composition.

Data on the object could also be useful well into the future, as there is a chance that Eros could collide with the earth in roughly 1.5m years.