Donald Brownlee, University of Washington
The NASA Stardust mission collected thousands of dust particles and small rocks from Comet Wild 2 and returned to them to Earth where they are being studied by scientists around the world. The comet formed beyond the orbit of Neptune and the particles released from it are believed to be samples of the early solar system that have been packed in ice for 4.6 billion years. The samples are complex and contain both materials that are older than the Sun as well as those that formed in the early solar system. A remarkable finding was the many of the small rocks in this ice-rich body were formed at very high temperature. Some formed close to the Sun and were transported beyond the most distant planets. The analysis of these small precious samples involve wide ranging microanalysis methods to determine elemental, chemical, mineralogical and isotopic compositions at micron and submicron size scales. The study of these complex fine-grained materials pose interesting challenges for a variety micro analysis techniques.
