Space Rock History Revealed

摘要

Calcium, aluminum-rich inclusions (CAIs) in meteorites are thought to be the oldest solids in the solar system, preserving clues to events that happened in the early solar nebula, before planets or other solids formed. Simon et al. (p. 1175) measured oxygen isotope variations within a CAI from the CV3 Allende meteorite. Both the inclusion's core and its rim show systematic variations in relative abundances of oxygen isotopes that approach the range that has been observed for all solids formed in the solar system. The observations imply that, as it formed, this CAI experienced distinct isotopic environments, possibly because it was transported through different regions of the solar nebula.