In January, NASA’s Stardust satellite returned to Earth with dust from the tail of comet Wild 2. The samples were collected with the aid of filters from Omega Optical Inc. of Brattleboro, Vt., as part of the onboard camera’s optical system.Approximately two years ago, the satellite passed near the comet, through a particle and gas coma, collecting samples and sending back images of the comet’s surface. The dust represents the first such material collected from a comet and from outside the Earth/moon system.