Scientists claim two of Earth’s doomsday events from before the dinosaurs may have been triggered by a supernova exploding in the Milky Way. For decades scientists have dubbed several of our planet’s largest mass extinction events – including 66 million years ago when a giant asteroid hit Earth and wiped out the dinosaurs – the ‘Big Five’.
Now Keele University boffins say two of these five mass extinctions – 445 million years ago and 372 million years ago – could have been sparked by supernovae in nearby space. A supernova is a powerful and bright explosion of a star, caused by them running out of ‘fuel’ and collapsing under their own weight – sending a shock wave of material out across the solar system.
Now studying these events, UK scientists claim one of these in the Milky Way would strip protective ozone from our atmosphere, exposing life to the sun’s harmful ultraviolet rays and acid rain and possibly causing a mass extinction of animal or plant life.
Their findings have been published in the Monthly Notices of the Royal Astronomical Society journal, after the researchers conducted a “census” of massive stars within a kiloparsec (around 3,260 light-years) of the Sun.
Dr Nick Wright, from Keele University, added: “Supernova explosions are some of the most energetic explosions in the Universe.
“If a massive star were to explode as a supernova close to the Earth, the results would be devastating for life on Earth. This research suggests that this may have already happened.
“We calculated the supernova rate close to Earth and found it to be consistent with the rate of mass extinction events on our planet that have been linked to external forces such as supernovae.”
In their landmark study, Wright and colleagues focused on a type known as ‘OB’ stars, which are hot, bright but short-lived.
They looked at the rate at which supernovae occur both within our galaxy—but, more specifically, within 65 light-years of Earth.
They then compared this with the rate of those famous ‘Big Five’ mass extinction events in the history of life on Earth, a planet thought to be 4.5 billion years old.
They are 1 – Late Ordovician (445-444 million years ago) that killed off 57 per cent of all life including bacteria and viruses and 85 per cent of marine organisms and the second-largest of the big five.
2 – Late Devonian (372-359 million years ago) which annihilated coral reefs and seabed living animals like jawless fish and shelled or exoskeleton sea creatures like trilobites and ammonoids.
3 – Permian-Triassic (252 million years ago) or the ‘Great Dying’ which saw 81 per cent of all marine species and 70 per cent of land vertebrate species wiped out.
4 – Triassic-Jurassic (201.3 million years ago) saw up to 75 per cent of all species extinct, including most of the large amphibians, leaving dinosaurs with little land competition.
5 – Cretaceous-Paleogene (66 million years ago) when an asteroid is thought to have hit the Earth and wiped 75 per cent of all species including the dinosaurs.
The study linked the earliest two of these five to possible supernovae events – the late Devonian and late Ordovician mass extinction events after current hypothesis links them to depletions in the Earth’s protective ozone layer.
The team have estimated that 0.4–0.5 supernovae occur in galaxies like the Milky Way each century—a slightly lower figure than previous estimates of two or three every 100 years.
Luckily, the only nearby stars capable of going supernovae in the next million years—Antares and Betelgeuse—are far enough away that we would not feel any effects.
According to the researchers, the findings are a “great” illustration of how massive stars have the capacity to both create and destroy life.
Lead author Dr Alexis Quintana, formerly from Keele University and now at the University of Alicante, said: “It is a great illustration for how massive stars can act as both creators and destructors of life.
“Supernova explosions bring heavy chemical elements into the interstellar medium, which are then used to form new stars and planets.
“But if a planet, including the Earth, is located too close from this kind of events, this can have devastating effects.”
* For more information visit – Quintana, A. L., Wright, N. J., & García, J. M. (2025). A census of OB stars within 1 kpc and the star formation and core collapse supernova rates of the Milky Way (No. arXiv:2503.08286). arXiv. https://doi.org/10.48550/arXiv.2503.08286
