Stardust floats gently to Earth

Scientists worldwide are toasting the successful return to Earth of NASA's Stardust mission - a seven-year jaunt during which the vehicle captured samples from comet Wild 2's tail and, the team hopes, some interstellar dust.

The 46kg sample capsule hit the Earth's atmosphere just before 10:00 GMT yesterday, having separated from the main spacecraft fours hours previously. At 105,000ft, its drogue parachute opened, providing some initial braking before the main 'chute deployed at 10,000 ft. The capsule finally hit the ground in the Utah desert at 10:12 GMT, travelling at roughly 10mph. It bounced three times before coming to rest on its side.

The helicopter-borne recovery team, guided by Stardust's onboard Ultra High Frequency beacon, used GPS and infrared imaging equipment to find the capsule in the complete darkness. It was then moved to a cleanroom at the Michael Army Air Field, Dugway Proving Ground, for "initial processing", before dispatch to NASA's Johnston Space Center in Houston.

Once there, its "Stardust Interstellar Dust Collector" - a silicon-based sponge called "aerogel", arranged in a disk-shaped mosaic of tiles about 16 inches in diameter and half-an-inch thick - will be put under an "automated microscope to digitally photograph the entire area of the aerogel in patches that can be viewed later in search of dust particles".

Which is where Joe Public can get in on the act. The University of California, Berkeley, is publishing the miscroscope's output via a "virtual microscope", allowing "anyone with an internet connection to scan some of the 1.5 million pictures of the aerogel for tracks left by speeding dust. Each picture will cover an area smaller than a grain of salt." There's more details on how you can get involved in spacedust-hunting in our previous report here.

Scientists, meanwhile, are licking their lips at the prospect of getting their hands on some comet dust. Five British institutions are involved in the project - Imperial College, Natural History Museum, Open University, University of Kent and University of Manchester. Dr Phil Bland of the Imperial College and Natural History Museum team enthused: "Its incredible that in a few days time we're going to have bits of comet in our lab - for me it's a dream come true, to have the opportunity to analyse samples like this. What is especially exciting is that we could be getting fundamental information about how the solar system formed, within just a few hours."

There's lots more Stardust material on the dedicated NASA website. ®