Stardust capsule returns to Earth

As BBC informs the US probe Stardust released the samples as it looped past the Earth after a three billion mile round trip.

The capsule plunged through the atmosphere and touched down in the Utah desert at 0312 (1012 GMT).

Scientists believe the pristine particles snatched from a comet and interstellar space will give insights into the origins of the Solar System.

It is the first time in history that a space mission has brought back such material.
The Stardust spacecraft released the 101lb (45kg) capsule at 0557 GMT as it flew past the Earth on its return from deep space.

Mission controllers at the US space agency Nasa Jet Propulsion Laboratory in Pasadena, California, clapped and cheered as the capsule began its plunge to Earth. Four hours after leaving the probe, the capsule entered the Earth's atmosphere 125 km (410,000ft) over the Pacific Ocean.

It reached speeds of 46,660kph (29,000mph) - the fastest re-entry of any manmade probe - and was visible from parts of the American northwest as a streak of light in the sky.
At about 32km altitude (105,000 feet), the capsule released a small parachute to slow its descent.

The main parachute opened at about 3km (10,000ft), and brought the capsule down to land on a military base southwest of Salt Lake City.

The samples are to be picked up by helicopter and flown to an army building, then to a special lab at Nasa's Johnson Space Center in Houston, Texas.

Meanwhile the mothership probe has gone into permanent orbit around the Sun, after its 4.7 billion km (3 billion miles) voyage around the Solar System.

Stardust was launched on its mission to capture dust and debris surrounding a comet in 1999. It swept up particles from Comet Wild 2 in January 2004, as it flew within 240km (149 miles) of the frozen body of ice and dust.

As part of its trip, the probe also captured a sprinkling of dust that would have originated in distant stars.

The comet and dust molecules were trapped in cells filled with a specially-developed ultra-light gel called aerogel.

The capsule is believed to contain about a million particles of comet and interstellar dust leftover from the birth of the Solar System.

The microscopic particles represent the first solid material returned to Earth from an extraterrestrial body since 1976, when the unmanned Soviet Luna 24 mission brought back moon rocks and soil.

Comets are thought to be cosmic "time capsules", containing material unchanged since the formation of the Sun and planets.

Some even think they may have seeded Earth with the chemical building blocks required for life.

"Stardust could provide a new window into the distant past," said Dr Simon Green of the PSSRI.

"Comets are made of ice and are very cold and have been very cold since they were formed. That protects the material of which they were made from any process of heating, so they haven't been changed since they were formed, right at the beginning of the formation of the Solar System.

"So we can have almost a little time capsule of what things were like 4.5 billion years ago."