New Measurement of the 60Fe Half-Life

We have made a new determination of the half-life of the radioactive isotope Fe-60 using high precision measurements of the number of Fe-60 atoms and their activity in a sample containing over 10(15) Fe-60 atoms. Our new value for the half-life of Fe-60 is (2.62 +/- 0.04) X 10(6) yr, significantly above the previously reported value of (1.49 +/- 0.27) X 10(6) yr. Our new measurement for the lifetime of Fe-60 has significant implications for interpretations of galactic nucleosynthesis, for determinations of formation time scales of solids in the early Solar System, and for the interpretation of live Fe-60 measurements from supernovaejecta deposits on Earth.