New research suggests that powerful star explosions, called supernovae, may have caused at least two mass extinctions in Earth’s history.
Scientists from Keele University believe that these massive blasts stripped away Earth’s ozone layer, leading to acid rain and harmful ultraviolet (UV) radiation from the sun.
This could have made life on Earth extremely difficult, killing off many species.
The researchers studied how often supernovae occur within 65 light-years of Earth and compared this with known extinction events.
Their findings support the idea that supernovae may have played a role in two major die-offs—the Ordovician extinction (445 million years ago) and the late Devonian extinction (372 million years ago).
The Ordovician extinction wiped out 60% of marine invertebrates when most life was still in the ocean.
The late Devonian event was even worse, killing about 70% of all species and changing the types of fish that lived in ancient waters.
Previous studies struggled to find a clear cause for these events. However, scientists had suspected that a weakened ozone layer could have been involved. This new study strengthens the theory that nearby supernova explosions could have been responsible.
Dr. Nick Wright, one of the researchers, explained that their calculations showed a match between the rate of nearby supernovae and the timing of mass extinctions. “If a massive star were to explode close to Earth, the effects would be devastating. This research suggests it may have already happened,” he said.
The good news? The study found that there are currently no stars close enough to pose a real danger. The two nearest stars that could explode—Antares and Betelgeuse—are over 500 light-years away. At that distance, a supernova wouldn’t harm Earth, according to computer models.
Supernovae happen when giant stars run out of fuel and collapse under their own gravity, creating the most powerful explosions in the universe. These explosions not only destroy, but also create—they scatter heavy elements like carbon and iron, which are essential for life.
Lead researcher Dr. Alexis Quintana pointed out this dual role: “Supernova explosions spread chemical elements that form new stars and planets, but if a planet is too close, the effects can be disastrous.”
The study, published in Monthly Notices of the Royal Astronomical Society, also helps scientists understand how stars and galaxies evolve. By mapping massive stars within a large section of the Milky Way, the researchers calculated how often supernovae occur and their potential impact on life.
This discovery highlights the surprising ways cosmic events shape life on Earth—not just in the past, but possibly in the future as well.
