Millions of years ago, multiple stars located some 325 light years from the Earth burst into spectacular supernovae. Though our planet was well beyond the 30-light-year kill zone of these explosions, stellar shrapnel was blown out with such force that it dusted the Earth with radioactive iron-60 isotopes centuries later.
By Becky Ferreira | MOTHERBOARD
Now, in new research published Wednesday in Nature, two international teams of scientists report that this isotopic signature has been discovered in 120 core samples extracted from the Pacific, Atlantic, and Indian Oceans. The find offers concrete proof that the fallout of ancient supernovae has been deposited on Earth, and may have even influenced our planet’s recent geological and biological history.
“It is now possible to ask key questions with some precision,” said Adrian Melott, an astrophysicist at the University of Kansas, in a Nature statement on the new studies. “For example, could these supernovae have had substantial effects on Earth’s climate and organisms—and perhaps even a role in human evolution?”