Near closes in on Eros

Surface features have fascinated scientists

The American spacecraft Near has moved into its closest orbit yet around the asteroid Eros, circling only 50 kilometres above the object's surface.

Scientists at the American space agency Nasa hope now to detect the various minerals that make up Eros.

The probe's laser rangefinder will also continue to scan the precise shape of the asteroid.

Getting the Near spacecraft so close to Eros has taken more than four years and has been a remarkable technological achievement.

The Near spacecraft has been beaming back pictures from the space rock for almost three months. The images show craters the size of cities and boulders as tall as tower blocks.

The potato-shaped lump of rock is around 30 kilometres long and scientists believe it may once have been part of a larger body, like a planet, which blew apart billions of years ago.

The Near mission was designed by Nasa to answer fundamental questions about the many asteroids and comets which come close to Earth's orbit.

It may contain clues about how the Earth and other planets were formed.