Cosmogenic Nuclides in Antarctic Meteorites

This chapter discusses applications to Antarctic meteorites of cosmogenic nuclides. Cosmogenic nuclides are nuclei produced by cosmic rays, mostly before the meteorites collided with Earth. They help us to estimate how long the meteorites were exposed to cosmic rays, a length of time called the cosmic ray exposure age, and the duration of a meteorite's stay on Earth, a length of time called the terrestrial age. From the 1970s onwards, the return of Antarctic meteorites gave an enormous boost to the study of meteoritics in general and of cosmogenic nuclides and cosmic-ray exposure histories in particular. With the investigation of Antarctic lunar meteorites has come improved understanding of meteoroid ejection process and the transit to Earth. Through their greater numbers and clustering, the exposure ages of Antarctic martian meteorites have helped to identify major launch events from Mars.