Comet dust samples a huge success: scientist

The Stardust space capsule has returned more than a million specks of dust from stars and comets, the mission's lead scientist said Thursday.

It's hoped the samples will yield clues to the makeup of a comet and the origins of the solar system.

"It exceeds all expectations. It's a huge success," said Donald Brownlee, an astronomy professor at the University of Washington.

The capsule's sample canister may contain "more than a million" specks, some of which may date back 4.5 billion years to the birth of the solar system.

When the sample canister was opened, scientists were surprised to see small, black particles. They expected to need a microscope to see the grains.

"We were totally overwhelmed by the ability to actually see this so quickly and so straightforwardly," Brownlee told a news conference.

A teaspoonful of the grains will be sent out to the international science community for analysis.

On Jan. 15, Stardust became the first spacecraft to return to Earth with comet dust. Two years ago, it flew through a halo of gas, dust and debris enveloping the comet Wild 2.

Comets come from deep space beyond Neptune and are composed of ice, dust and debris in a mix virtually unchanged since the solar system formed.