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According to new research from Keele University and the Universidad de Alicante, near-Earth explosions of giant O- and B-type stars occur at a rate of 2.5 per one billion year; this result supports the view that such events could have caused one or more of the recorded mass extinction events on Earth.
Artist’s impression of Zeta Puppis, an O-type star approximately 1,400 light-years away in the constellation Puppis. Image credit: Tahina Ramiaramanantsoa.
Keele University and Universidad de Alicante astronomers believe a supernova explosion close to Earth could be to blame for both the Late Devonian and Ordovician extinction events, which occurred 372 and 445 million years ago respectively.
The Ordovician extinction killed 60% of marine invertebrates at a time when life was largely confined to the sea, while the Late Devonian wiped out around 70% of all species and led to huge changes in the kind of fish that existed in our ancient seas and lakes.
Past research has failed to identify a clear cause for either event, although they are thought to have been linked to the depletion of Earth’s ozone layer, which could have been triggered by a supernova.
The new study found that the rate supernovae occur near to our planet is consistent with the timings of both mass extinctions.
“Supernova explosions bring heavy chemical elements into the interstellar medium, which are then used to form new stars and planets,” said Keele University’s Dr. Alexis Quintana, lead author of the study.
“But if a planet, including the Earth, is located too close to this kind of event, this can have devastating effects.”
“Supernova explosions are some of the most energetic explosions in the Universe,” said Dr. Nick Wright, also of Keele University.
“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.”
An artist’s impression of HR 6819, a close binary consisting of a stripped B-type star (background) and a rapidly rotating Be star (foreground). Image credit: ESO / L. Calçada.
The astronomers came to their conclusion after carrying out a census of massive OB stars within a kiloparsec (around 3,260 light-years) of the Sun.
They were studying the distribution of these stars to learn more about how star clusters and galaxies form by using the Milky Way itself as a benchmark, and the rate at which these stars form in our Galaxy.
This census allowed the researchers to calculate the rate at which supernovae occur within the Galaxy, which is important for observations of supernovae, and the production of supernova remnants and massive stellar remnants such as black holes and neutron stars throughout the Universe.
The data will also be useful for future development of gravitational wave detectors, which are a useful tool for scientists studying the structure and origins of the universe.
As part of this the research team calculated the supernova rate within 20 parsecs (65 light-years) of the Sun, and compared this with the approximate rate of mass extinction events on Earth that have previously been attributed to nearby supernovae.
This excludes extinction events linked to other factors such as asteroid impacts or the ice ages.
Comparing these datasets, the experts found that their research supported the theory that a supernova explosion was responsible for both the Late Devonian and Ordovician extinction events — two of the five known mass extinctions in Earth’s history.
“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,” Dr. Wright said.
Astronomers believe about one or two supernovae — or possibly at a rate even lower than that — occur each century in galaxies like the Milky Way, but the good news is there are only two nearby stars which could go supernova within the next million years or so: Antares and Betelgeuse.
“However, both of these are more than 500 light-years away from us and computer simulations have previously suggested a supernova at that distance from Earth likely wouldn’t affect our planet,” the authors said.
Their study will be published in the Monthly Notices of the Royal Astronomical Society.
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Alexis L. Quintana et al. 2025. A census of OB stars within 1 kpc and the star formation and core collapse supernova rates of the Milky Way. MNRAS, in press; arXiv: 2503.08286v1
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