A rare, carbon-rich meteorite that fell into a frozen Canadian lake early last year (SN: 4/8/00, p. 235) ranks as the most pristine of such specimens ever found, report the researchers who conducted the first chemical analyses.
The Taglish Lake meteorite is classified as a carbonaceous chondrite, one of the first group of meteorites to have formed in the solar system. The rock contains buckyballs–soccerballshaped molecules made of carbon–filled with the inert gases helium and argon. The ratio of helium to argon that the scientists measured matches the ratio that astronomers calculate was present in the cloud of gas and dust that surrounded the young sun and provided the raw material for the planets.
That finding indicates the Tagish Lake meteorite has preserved chemical elements that developed or accumulated early in the history of the solar system, according to chemist Sandra Pizzarello of Arizona State University in Tempe and her colleagues. They report th