Radiocarbon beyond this world

In this paper we review the production of radiocarbon and other radionuclid es in extraterrestrial materials. This radioactivity can be produced by the effects of solar and galactic cosmic rays on solid material in space. In a ddition, direct implantation at the lunar surface of C-14 and other radionu clides can occur. The level of C-14 and other radionuclides in a meteorite can be used to determine its residence time on the Earth's surface, or "ter restrial age". C-14 provides the best tool for estimating terrestrial ages of meteorites collected in desert environments. Age control allows us to un derstand the time constraints on processes by which meteorites are weathere d, as well as mean storage times. Third, we discuss the use of the differen ce in C-14/C-12 ratio of organic material and carbonates produced on other planetary objects and terrestrial material. These differences can be used t o assess the importance of distinguishing primary material formed on the pa rent body from secondary alteration of meteoritic material after it lands o n the earth.