Series of supernovae showered Earth with radioactive debris

Sydney: An international team of scientists has found evidence of a series of massive supernovae, or explosions after a star runs out of fuels and leads to creation of many radioactive heavy elements, near our solar system which showered the earth with radioactive debris millions of years ago.

Debris that includes radioactive iron-60 in sediment and crust samples between 3.2 and 1.7 million years ago have been found from the Pacific, Atlantic and Indian Oceans. "The iron-60 was concentrated in a period between 3.2 and 1.7 million years ago, which is relatively recent in astronomical terms," said lead researcher Anton Wallner, nuclear physicist at the Australian National University (ANU) in Australia.