Institute for Advanced Study Astrophysics Seminar

Stardust, the NASA comet sample return mission, obtained thousands of particles from comet Wild 2. Detailed laboratory study of this material from a body that formed beyond Neptune is providing new insight into the origin of comets and crystalline silicates in circumstellar disks. The comet contains abundant refractory materials that apparently formed in the inner solar system and were transported to Kuiper belt. Large-scale radial transport processes carried familiar components found in meteorites, like fragments of chondrules and Calcium Aluminum Inclusions, to the edge of the solar system. The comet also contains ultra-refractory compounds that are the first solids to condense from hot solar-composition gas. Pre-solar grains (stardust!) have been found in the comet sample but their abundance appears to be lower than found in asteroidal meteorites from the inner solar system. The new view of this Jupiter family comet is that it is a remarkable mix of ices formed ~50K and inner solar system ''rocky'' materials that formed at 1400-2000K!