It’s been decades since we brought moon rocks back to Earth, but those Apollo-era artifacts still have a few secrets left to tell.
Space reports that a new study of the moon rocks picked up during the Apollo missions suggests that a nearby supernova likely blasted the Earth a few million years ago. The study goes on to posit that the stellar exposition could’ve been a key factor in the evolution of life on Earth (by changing the climate, radiation, clouds, etc.). We always wondered why Earth was so special, and it turns out a massive explosion from a dying star millions of years ago could be one of the reasons.
The study looked at the iron-60 content in the moon rocks, since scientists know supernovas generate large amount of that specific type of iron. Supernovas are by far the most efficient ways to produce iron-60, and by these findings in the moon rocks, it seems to indicate that is most likely what caused it to occur. The prevailing theory is that debris from a supernova “sprayed” the Earth (and solar system) millions of years ago.
They managed to narrow that window of time down to a few million years because iron-60 only has a half-life of 2.6 million years, so that means it must’ve happened at some point in the past 4 (or so) million years. #Science.
The study was detailed in Physical Review Letters, if you’re up for some light scientific journal reading.
*The image below is the remnant of a supernova, just for reference: