Published online by Cambridge University Press: 06 January 2010
The discovery that the short-lived radionucleide 60Fewas present in the oldest meteorites suggests that the formation ofthe Earth closely followed the death of a massive star.I discuss three astrophysical origins: winds from an AGB star,injection of supernova ejecta into circumstellar disks,and induced star formation on the boundaries of HII regions.I show that the first two fail to match the solar system 60Fe abundance in the vast majority of star forming systems.The cores and pillars on the edges of HII regions arespectacular but rare sites of star formationand larger clumps with masses 103-4 M๏ at tensof parsec from a supernova are a more likely birthenvironment for our Sun.I also examine γ-ray observations of 60Fe decayand show that the Galactic background could account for the low endof the range of meteoritic measurements if the massive starformation rate was at least a factor of 2 higher 4.6 Gyr ago.