The great isotopic dichotomy of the early Solar System.

The isotopic composition of meteorites and terrestrial planets holds important clues about the earliest history of the Solar System and the processes of planet formation. Recent work has shown that meteorites exhibit a fundamental isotopic dichotomy between (NC) and (CC) groups, which most likely represent material from the inner and outer Solar System, respectively. Here we review the isotopic evidence for this NC-CC dichotomy, discuss its origin, and highlight the far-reaching implications for the dynamics of the solar protoplanetary disk. The NC-CC dichotomy combined with the chronology of meteorite parent body accretion mandate an early and prolonged spatial separation of inner (NC) and outer (CC) disk reservoirs, lasting between ~1 and ~4 million years (Myr) after Solar System formation. This is most easily reconciled with the early and rapid growth of Jupiter's core, inhibiting significant exchange of material from inside and outside its orbit. The growth and migration of Jupiter also led to the later implantation of CC bodies into the inner Solar System and, therefore, can explain the co-occurrence of NC and CC bodies in the asteroid belt, and the delivery of volatile- and water-rich CC bodies to the terrestrial planets.