Scientists working at Washington University in St. Louis have discovered two tiny grains of silica (SiO2; the most common constituent of sand) in meteorites that fell to earth in Antarctica. Because of their isotopic composition these two grains are thought to be pure samples from a massive star that exploded before the birth of the solar system, perhaps the supernova whose explosion is thought to have triggered the collapse of a giant molecular cloud, giving birth to the Sun.
Thomas J. Bernatowicz, professor of physics in Arts & Sciences, will deliver the McDonnell Distinguished Lecture at 7 p.m. Wednesday, April 10, in Room 105, Steinberg Hall, at Washington University in St. Louis. He will discuss what cosmic dust carried to Earth by meteorites has revealed about the creation of the elements by stars and supernovae. The St. Louis community is cordially invited to the lecture, which is sponsored by the McDonnell Center for the Space Sciences.
Ernst K. Zinner, research professor of physics and of earth and planetary sciences, both in Arts & Sciences at Washington University in St. Louis, has received a three-year, $1,380,000 grant from the National Aeronautics and Space Administration to study presolar grains in a sample of the Murchison meteorite, a primitive meteorite that fell to Earth near the town of Murchison, Australia, in 1969. Presolar grains are literally tiny bits of stars — stardust — that were born and died billions of years ago, before the formation of the solar system. Some carry within them clues to the process of nucleosynthesis by which new elements are forged in the bellies of supernovae.
NASA/JPL-Caltech/E.Churchwell (U. of WisconsinThe nebula RCW49 is a nursery for newborn stars and exists in circumstellar space, where chemistry is done for the very first time.Picture a cool place, teeming with a multitude of hot bodies twirling about in rapidly changing formations of singles and couples, partners and groups, constantly dissolving and reforming. If you were thinking of the dance floor in a modern nightclub, think again. It’s a description of the shells around dying stars, the place where newly formed elements make compounds and life takes off, said Katharina Lodders, Ph.D., research associate professor of earth and planetary sciences in Arts & Sciences at Washington University in St. Louis.
Ernst K. Zinner, Ph.D., research professor of physics and of earth and planetary sciences, both in Arts & Sciences, at Washington University in St. Louis, provided an overview of the study of “Stardust in the Laboratory” Monday, Feb. 20, 2006, at the annual meeting of the American Association for the Advancement of Science (AAAS), held in St. Louis. He also participated in the AAAS “Exploring a Dusty Cosmos” press briefing that morning.
Christine Floss, Ph.D., and Frank Stadermann, Ph.D., examine data on the NanoSIMS in Compton Hall.A collaborative team of researchers including two from WUSTL have discovered what turns the lights out from space. They have discovered that organic carbon and amorphous silicates in interstellar grains embedded within interplanetary dust particles (IDPs) are the carriers of the astronomical 2175 Å extinction line, which occurs at a wavelength of 2175 Angstroms and blocks starlight from reaching the Earth.