"Mirror-Image" Isotope Anomalies in Meteorites Reveal Poorly Mixed SN Debris at the Birth of the Solar System

Mass number, A

This illustrates the “mirror-image” (+ and -) isotopic anomaly patterns seen in Ba, Nd and Sm from meteorites. Ba, Nd, and Sm in SiC inclusions of the Murchison meteorite (bottom) are enriched in isotopes made by slow-neutron capture, the s-process. These same elements in inclusion EK-1-4-1 of the Allende meteorite (top) are enriched in isotopes made by rapid nuclear reactions in the supernova, the r- and p-processes [F. Begemann, “Isotopic abundance anomalies and the early solar system” in Origin and Evolution of the Elements, ed. Prantos, N., Vangioni-Flam, E. and Cassé, M., Cambridge University Press, Cambridge, UK (1993) pp. 518-527].