Scientists from Keele University have found strong evidence that some of Earth’s past mass extinctions could have been caused by nearby supernova explosions—massive star explosions in the Milky Way.
Their study, published in the Monthly Notices of the Royal Astronomical Society, suggests that these cosmic events might have wiped out life on Earth millions of years ago.
The research team conducted a detailed survey of massive stars within about 3,260 light-years of the Sun.
These stars, known as OB stars, are important for understanding how galaxies and star clusters form.
The scientists also studied how often these stars explode as supernovae, which helps predict the formation of black holes, neutron stars, and supernova remnants. This information is useful for improving gravitational wave detectors, which help scientists study the universe.
One key part of their study was calculating how often supernovae occur within 65 light-years of Earth. They then compared this with the rate of past mass extinction events that are not linked to asteroids or ice ages.
The results showed a strong match, suggesting that supernovae could have played a role in extinctions, such as those in the late Devonian period (372 million years ago) and the late Ordovician period (445 million years ago).
A nearby supernova could strip away Earth’s ozone layer, exposing plants and animals to dangerous ultraviolet radiation from the Sun. This would have been devastating for life, possibly leading to mass extinctions.
Dr. Alexis Quintana, the lead author of the study, explained: “Massive stars can both create and destroy life. Their explosions spread heavy elements that help form new stars and planets, but if a planet like Earth is too close, the effects can be disastrous.”
Dr. Nick Wright from Keele University added: “Supernova explosions are among the most powerful events in the universe. If one were to happen near Earth, it could be catastrophic. Our research suggests that this might have already happened in the past.”
This study provides a new perspective on the history of life on Earth, showing that cosmic events beyond our planet could have had a major impact on evolution and extinction.
