Called Chicxulub, it straddles the Yucatan peninsula and the Gulf of Mexico. Samples of the impact melt collected by drilling into the crater give an age of 65 million years. This map shows the variations in gravity over the buried Chicxulub structure. The crater is about 200 kilometers across. The white line indicates the shoreline between the Yucatan and the Gulf of Mexico.
Fullerenes are unique carbon molecules with structures that resemble geodesic domes.
The long name is usually shortened to fullerenes or buckyballs. The soccer-ball structures of fullerenes allow the molecules to trap gases inside. Measurements of the gases in Bob Poreda's laboratory showed that the Cretaceous-Tertiary samples contain helium and argon with isotopic abundances like those in meteorites. The compositions are much different from those in typical Earth rocks or sediments. In fact, Becker and her coworkers argue that the isotopes and the buckyballs that house them must have formed in stars, long before our star and its Solar System formed.