• DOI:10.1038/nature17196
• Corpus ID: 4465810

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

@article{Wallner2016RecentNS,
  title={Recent near-Earth supernovae probed by global deposition of interstellar radioactive 60Fe},
  author={Anton Wallner and Jenny Feige and Norikazu Kinoshita and M. Paul and Leslie Keith Fifield and Robin Golser and Maki Honda and Ulf Linnemann and Hiroyuki Matsuzaki and Silke Merchel and Georg Rugel and Stephen G. Tims and Peter Steier and Takeyasu Yamagata and Stephan Winkler},
  journal={Nature},
  year={2016},
  volume={532},
  pages={69 - 72}
}

• A. Wallner, J. Feige, +12 authors S. Winkler
• Published 4 February 2016
• Physics, Geology
• Nature

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 century). Recent massive-star and supernova activity in Earth’s vicinity may be traced by radionuclides with half-lives of up to 100 million years, 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), which is ejected in supernova explosions and winds from massive stars. Here we report that the 60Fe signal observed previously in deep-sea crusts 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 60Fe 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.