Nucleosynthetic heterogeneities in meteorites

Nucleosynthetic isotope anomalies are a powerful tool for examining the birth environment of the Sun and the earliest proto-Solar processes. As a result of considerable development and enhancement of analytical capabilities at the turn of the century, the last 15years have seen significant steps in our understanding of both the extent of isotopic variation within the Solar System and the interpretation and implications of these variations. Unequivocal nucleosynthetic isotope anomalies have been observed in wide array of elements covering a broad mass range, chemical behavior and nucleosynthetic production mechanisms. These data allow for the tracing of material between different regions of the proto-Solar nebula and for the testing of genetic relationships between different meteorite groups. They can also provide clues as to the variety of stellar environments which may have contributed to the pre-Solar molecular cloud. In this chapter, I describe the nucleosynthetic origins of an illustrative selection of elements and the mixing of isotopically anomalous material into the early Solar System. I discuss the variation of isotope anomalies between different meteorite groups and meteorite components and summarize the major implications of these data. Finally, I examine the implications of anomalies in meteorites for the terrestrial building blocks and the formation of habitable terrestrial planets.