Stardust researchers studying the aerogel collector (centre) returned to Earth from the Stardust spacecraft. The aerogel was extended into the dusty coma of the comet Wild-2 by the Stardust spacecraft in January 2004. The collector returned to Earth in a capsule on 15th January 2006. Aerogel is a solid with extremely low density, designed to slow and stop the dust particles without damaging them. Comets are relics from the formation of the solar system, and study of their composition could provide information on its history. Donald Brownlee, the principal investigator with the University of Washington, is giving victory salutes to celebrate the arrival of the aerogel.