2008/10/07 by Nicolas Dauphas, David L. Cook, A. Sacarabany +6 · 1 citation
Physics and Astronomy · Earth and Planetary Sciences · #Astro and Planetary Science #Planetary Science and Exploration #Geology and Paleoclimatology Research
paper · pdf · doi:10.1086/589959
openalex publication_date 2008/10/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Among extinct radioactivities present in meteorites, 60 Fe ( t 1/2 = 1.49 Myr) plays a key role as a high-resolution chronometer, a heat source in planetesimals, and a fingerprint of the astrophysical setting of solar system formation. A critical issue with 60 Fe is that it could have been heterogeneously distributed in the protoplanetary disk, calling into question the efficiency of mixing in the solar nebula or the timing of 60 Fe injection relative to planetesimal formation. If this were the case, one would expect meteorites that did not incorporate 60 Fe (either because of late injection or incomplete mixing) to show 60 Ni deficits (from lack of 60 Fe decay) and collateral effects on other neutron-rich isotopes of Fe and Ni (coproduced with 60 Fe in core-collapse supernovae and AGB stars). Here, we show that measured iron meteorites and chondrites have Fe and Ni isotopic compositions identical to Earth. This demonstrates that 60 Fe must have been injected into the protosolar nebula and mixed to less than 10% heterogeneity before formation of planetary bodies.