supernovae

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.

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.