Scientists Suggest Supernovas May Have Twice Wiped Out Life on Earth

Mass extinctions have shaped life on Earth for hundreds of millions of years—but we still don’t fully understand what caused all of them. Now, a new study suggests that violent supernova explosions may have played a role in at least two of these catastrophic events.

Supernovas occur when massive stars die in a fiery explosion, blasting radiation and cosmic debris into space. If one happens close enough to Earth, it could strip away our ozone layer, leaving life vulnerable to deadly radiation from space. That’s exactly what researchers think might have happened during two of Earth’s biggest die-offs:

• The Late Devonian extinction (~372 million years ago) – When early land plants and armored fish were wiped out.

• The Late Ordovician extinction (~445 million years ago) – When about 85% of life in the oceans vanished.

So, What Did the Scientists Actually Find?

The study, published in the Monthly Notices of the Royal Astronomical Society, looked at how often supernovas occur within 65 light-years of Earth. Their calculations suggest that one or two of these cosmic explosions likely happened in the past 500 million years—right when these mass extinctions occurred.

This led Nick Wright, a co-author of the study and astrophysicist at Keele University, to say:"It's a lot more feasible to think that this could be an effect that could affect extinction events."

The lead researcher, Alexis Quintana, also pointed out the paradox of supernovas—they help create life by spreading heavy elements needed for new stars and planets, but they can also destroy life if they explode too close.

The Missing Piece: Hard Evidence

While this theory is exciting, there’s no direct proof yet that a supernova caused these extinctions. Scientists like Mike Benton from the University of Bristol say they need better dating methods to line up a supernova event with an extinction.

Another scientist, Paul Wignall, says the key could be finding "supernova fingerprints"—specific elements in ancient rock layers that could only come from a stellar explosion. For example, the presence of iron-60 (a rare radioactive form of iron made in supernovas) in sediments from the extinction periods could be the missing "smoking gun."

We Know Space Rocks Can Do It

One mass extinction event we do have clear evidence for is the one that wiped out the dinosaurs 66 million years ago. That event was caused by a city-sized asteroid that smashed into what is now Mexico. Scientists figured this out after discovering a layer of iridium-rich rock—a chemical found in meteorites but rare on Earth.

To prove the supernova theory, scientists need to find something similar—maybe iron-60 or plutonium in the ancient rock layers that coincide with extinction events.

Could a Supernova Wipe Us Out Today?

Don’t panic—there are no supernovas expected near Earth anytime soon. The closest massive stars, like Betelgeuse, are still far enough away that their eventual explosion won’t pose a serious threat. But if a supernova did go off close enough, it could be catastrophic—stripping away the ozone layer and bombarding Earth with radiation.

For now, the idea that past supernovas may have caused mass extinctions is still just a hypothesis. But if scientists find evidence of supernova debris in ancient rocks, it could rewrite what we know about the history of life on Earth—and how the universe itself can be both creator and destroyer.