Field Museum researchers at the Robert A. Pritzker Center for Meteoritics and Polar Studies have received a second target foil from the Interstellar Dust Collector onboard NASA's Stardust Mission - that returned the first solid extraterrestrial material to Earth from beyond the Moon.
The new aluminum foil – which measures about 14 x 2 mm – was successfully imaged using the Field Museum scanning electron microscope in order to locate impact craters from interstellar dust particles. The first Stardust foil from NASA was imaged using the Field Museum electron microscope earlier this year. In the coming months, crater candidates identified in preliminary analysis will be reimaged at higher resolution. Results from analysis of both foils will be presented at in December 2011 at the Fall Meeting of the American Geophysical Union in San Francisco.
“Interstellar foils need to be imaged and searched carefully, since craters are extremely small - on the order of one micron,” says Asna Ansari, who has been working as an intern with Robert A. Pritzker Assistant Curator for Meteoritics and Polar Studies Philipp Heck (Geology) on the Stardust project since January 2011. “We're searching for impact craters of the first samples of contemporary interstellar dust ever returned to earth.”
The Field Museum group at the Robert A. Pritzker Center for Meteoritics and Polar Studies is part of the Interstellar Stardust Preliminary Examination Team, an international collaborative effort to identify interstellar dust captured by the collector flown onboard NASA's Stardust spacecraft.