Skip to main content

Recent near-Earth supernovae probed by global deposition of interstellar radioactive 60 Fe

129Citations
Citations of this article
94Readers
Mendeley users who have this article in their library.

Abstract

The rate of supernovae in our local Galactic neighbourhood within a distance of about 100 parsecs from Earth is estimated to be one every 2-4 million years, based on the total rate in the Milky Way (2.0 ± 0.7 per century1,2). Recent massive-star and supernova activity in Earth's vicinity may be traced by radionuclides with half-lives of up to 100 million years3-6, if trapped in interstellar dust grains that penetrate the Solar System. One such radionuclide is 60Fe (with a half-life of 2.6 million years)7,8, which is ejected in supernova explosions and winds from massive stars1,2,9. Here we report that the 60Fe signal observed previously in deep-sea crusts10,11 is global, extended in time and of interstellar origin from multiple events. We analysed deep-sea archives from all major oceans for 60Fe deposition via the accretion of interstellar dust particles. Our results reveal 60 Fe interstellar influxes onto Earth at 1.5-3.2 million years ago and at 6.5-8.7 million years ago. The signal measured implies that a few per cent of fresh 60Fe was captured in dust and deposited on Earth. Our findings indicate multiple supernova and massive-star events during the last ten million years at distances of up to 100 parsecs.

Cite

CITATION STYLE

APA

Wallner, A., Feige, J., Kinoshita, N., Paul, M., Fifield, L. K., Golser, R., … Winkler, S. R. (2016). Recent near-Earth supernovae probed by global deposition of interstellar radioactive 60 Fe. Nature, 532(7597), 69–72. https://doi.org/10.1038/nature17196

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free