NASA returns rocks from a comet.
Cometary particles returned by the Stardust Discovery Mission are primarily silicate materials of solar system origin. Some of the grains were formed at high temperatures close to the Sun, but then transported far out to the Kuiper belt region of the solar system before being incorporated in the comet.
Burnett
Don S
DS
Department of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA. burnett@gps.caltech.edu