Supernovas are some of the most powerful and energetic events in the entire Universe. When a dying star explodes you wouldn’t want to be anywhere nearby—fresh elements are nice and all, but the energy and radiation from a supernova would roast any planets within tens if not hundreds of light-years in all directions. Luckily for us we’re not in an unsafe range of any supernovas in the foreseeable future, but there was a time not very long ago (in geological terms) that these stellar explosions occurred nearby (in astronomical terms) and in 2016 scientists found the “smoking gun” evidence at the bottom of the ocean.
What’s more, the arrival of the iron-rich fallout from those stellar explosions seems to coincide with ancient global temperature changes*, the most recent dated near the start of the last major ice age which brought lower sea levels, widespread glaciation…and eventually the rise of the first modern humans.
Read more at Universe Today here: Nearby Supernovas Showered Earth With Iron
*Note: the changes in climate referred to here are not the same as the climate change we are witnessing today. Not only are we now seeing rapid warming of land and sea temperatures globally, but today’s forcings are the result of increasing greenhouse gases like carbon dioxide in the atmosphere—not radioactive iron from exploding stars.