Search

The article presents a speech by Lawrence Grossman, professor in Geophysical Sciences at the University of Chicago in Illinois, delivered at the Meteoritical Society annual meeting, held in Nancy, France, July 16, 2009, in which he acknowledged the persons and institutions who contributed to his achievement of receiving the Leonard Medal award which include Edward Anders, the University of Chicago, and the National Aeronautics and Space Administration (NASA).

Interstellar silicon carbide grains in meteorites provide a novel means for studying the carbon-star population of about 5 x 10 9 years ago. Their 12C/13C ratios differ greatly from the solar value but resemble those of present-day carbon stars, implying little change in galactic 13C inventory. Isotope data on nitrogen and silicon suggest that the silicon carbide grains come mainly from red giants, with small contributions from novae. [ABSTRACT FROM AUTHOR]

The article discusses the properties, detectability and origin of interstellar diamonds in meteorites. According to the author, laboratory studies suggest that microdiamonds will be quite subtle in interstellar space, being detectable only if >10 percent of the carbon is present as diamond. The diamonds evidently formed by condensation in cool stellar atmosphere, and were then impregnated with isotopically anomalous noble gases from supernova.