The concept of space and the universe we find ourselves in can be a bit daunting and intimidating to think about, mainly because no human on Earth today can really fathom just how small we are on the cosmic scale.
Sure, we can sort of think about it, but when there’s a supermassive black hole that is 17 billion times the mass of the sun floating around somewhere out there, eating up everything unfortunate enough to come near it, how clear is it really?
Supernovas, which are when massive stars explodes in dramatic fashion, are one of the great events that occur naturally in space. These explosions are usually so big, that if you’re within 75 light-years of one, in any direction, you get incinerated.
But, one cool aspect of these explosions is that they create new elements, and variations of elements, that get blasted out into space in every direction.
Which is exactly how we found iron-60, an isotope of iron that scientists have found in pockets of ocean sediment across the Atlantic, Pacific and Indian Oceans.
Supernova modeling indicates that millions of years ago, two stars supernova’d, resulting in a debris storm of elements raining down on Earth. Astronomers have calculated that the first explosion likely happened 2.3 million years ago and the second one happened about 1.5 million years ago.
Two new papers (this one and this one) detailing the discovery have been published in Nature journal, and they suggest that the stars couldn’t have been more than 300 light-years away from Earth.
Adrian Melott, an astronomer who was not involved in the research, says that “the events weren’t close enough to cause a big mass extinction or severe effects, but not so far away that we can ignore them either. We’re trying to decide if we should expect to have seen any effects on the ground on the Earth.”