Comet dust capsule heads for Earth

A space capsule carrying comet dust is due to return to Earth in a mission scientists hope will shed light on the origins of the solar system.

NASA’s Stardust spacecraft, hovering 69,000 miles in space, released the shuttlecock-shaped capsule late last night putting it oncourse for a blazing re-entry today.

If successful, the mission will mark the first time a spacecraft has flown into deep spaceand brought back tiny fragments of a comet. Most of the granules are so small that a microscope will be required to study them.

The capsule will spin in free fall until it enters the atmosphere and parachutes down in the Utah desert. Its searing return at about 29,000 mph will be the fastest re-entry of any man-made probe.

The Stardust mothership will remain in permanent orbit around the sun.

Comets are frozen bodies of ice and dust that formed soon after a gaseous disk collapsed to create the sun and planets 4.6 billion years ago. Comets formed from what was left over, and studying them could shed light on the solar system’s birth.

The cosmic samples were gathered from comet Wild 2 in 2004 during Stardust’s seven-year journey. The spacecraft used a tennis racket-sized collector mitt to snatch the dust and store it in an aluminium canister.

The mission, managedby NASA’s Jet Propulsion Laboratory, cost £176m.