Stardust space probe cleans up comet-tail dust for NASA

AN American space probe has entered the shimmering tail of a comet and is collecting hundreds of dust particles which will be returned to Earth for analysis.

The National Aeronautics and Space Administration says its Stardust spacecraft will pass within 186 miles of the comet Wild 2 as it flies through the cloud that envelops the dirty ball of ice and rock.

Scientists expected the probe to make its closest approach at about 7.40pm last night, while travelling at a speed of 13,650 mph.

Stardust was designed to gather hundreds if not thousands of dust particles streaming from Wild 2 (pronounced Vilt-2) during the flyby 242 million miles from Earth.

NASA scientists are eager to study the dust since it represents pristine examples of the building blocks of our solar system, preserved for billions of years by the cold of space.

They also believe the dust contains many of the organic compounds necessary for life. Comets that pelted the Earth long ago could have delivered those molecules to our planet.

“This could prove to be a pivotal time for science, a remarkable opportunity to gather evidence that might actually tell us how the planets formed and give us clues about how life on Earth began,” said Donald Brownlee, a University of Washington astronomer and the main scientist for the £120 million (€170m) mission.

The spacecraft should also take multiple images of the comet’s tiny nucleus, believed to be just 3.4 miles across. If successful, Stardust will become only the third spacecraft to capture such a close view of the dark heart of a comet, normally obscured by a bright veil of dust and gas.

Protective bumpers will shield the unmanned spacecraft as it ploughs through that veil at 13,650 mph. A tennis racket-shaped canister packed with a material called aerogel will capture the particles during the flyby. Aerogel is 99.8% air, making it the world’s lightest solid.

The canister already has swept up bits of interstellar dust since the spacecraft’s 1999 launch.

In 2006, Stardust will jettison the canister during a flyby of Earth. The canister and its extraterrestrial cargo should fall over Utah.

There, southwest of Salt Lake City, the National Aeronautics and Space Administration plans for a helicopter to pluck the parachuting package from the sky.

Scientists are hoping to analyse the particles for their chemical, elemental, isotopic and mineral composition.