The first comet sample-return mission is still revealing secrets about its icy target — even 18 years after bringing to Earth a precious cargo for scientists to dissect.
After launching in 1999, NASA's Stardust mission rendezvoused with the comet named 81P/Wild 2 (81P/ means it was the 81st periodic comet to be recognized) in 2004, capturing thousands of tiny dust particles from the comet's tail in a collector made from an ultralight material called "aerogel." On Jan. 15, 2006, Stardust returned the sample capsule to Earth, which then parachuted down toward a soft-landing in Utah. Those transported particles of comet dust are still being analyzed today.
