Scientists have used samples from the moon to confirm a supernova explosion that happened in the neighbourhood of our solar system about two million years ago.

A star exploded in a supernova close to our solar system and its traces can still be found today in the form of an iron isotope found on the ocean floor. Now scientists at the Technical University of Munich, and their colleagues from the US, have found increased concentrations of this supernova-iron in lunar samples as well. They believe both discoveries to originate from the same stellar explosion.

A dying star ends its life in a cataclysmic explosion, shooting the majority of the star’s material, new chemical elements created during the explosion, out into space. One or more such supernovae appear to have occurred close to our solar system approximately two million years ago.

Evidence of the fact has been found on earth in the form of increased concentrations of the iron isotope 60Fe detected in Pacific Ocean deep-sea crusts and in ocean-floor sediment samples.