Ron Ceeders, a Lockheed Martin technician, unbolts a canister containing comet dust from the Stardust capsule in a clean room Sunday in Dugway Proving Ground, Utah.

Dugway Proving Ground, Utah ? After a seven-year journey, a NASA space capsule returned safely to Earth on Sunday with the first dust ever fetched from a comet, a cosmic bounty that scientists hope will yield clues to how the solar system formed.

The capsule’s blazing plunge through the atmosphere lit up parts of the western sky as it capped a mission in which the Stardust spacecraft swooped past a comet known as Wild 2.

“This is not the finish line. This is just the intermediate pit stop,” said project manager Tom Duxbury of the Jet Propulsion Laboratory, which managed the $212 million mission.

About a million dust particles are believed to be inside a sealed canister.

The next stop for the capsule is the Johnson Space Center in Houston, where scientists will unlock its canister later this week. After a preliminary examination, they will ship the particles to laboratories all over the world for further study.