Scientists are exploring the possibility that powerful cosmic events, such as supernovae from nearby giant stars, may have played a role in Earth’s past mass extinction events. Recent research from Kiel University has linked two significant extinction events—the late Devonian (372 million years ago) and the Ordovician (445 million years ago)—to potential supernova activity. These events saw drastic reductions in biodiversity, with the Devonian period eliminating around 70% of species and the Ordovician period 60% of marine life.
The researchers have conducted a “census” of giant stars, finding frequencies of supernovae within roughly 3,260 light years from Earth that coincide with the timing of these historical extinctions. They suggest that nearby supernovae could erode the ozone layer, allowing harmful solar radiation to reach the Earth’s surface, which could have devastating effects on life.
While supernova events occur at a rate of 1-2 per century in galaxies like the Milky Way, the likelihood of an explosion occurring near Earth remains low. Nonetheless, researchers caution that stars like Antares and Betelgeuse could potentially pose a threat in the distant future if they become supernovae.
This study not only aims to deepen the understanding of mass extinctions but also seeks to improve models predicting the behavior of large stars and the gravitational waves generated by their explosions. Various questions remain about the environmental impacts of supernovae and their long-term effects on life on Earth, prompting ongoing research in the field. The findings were published in the Royal Astronomical Society’s Monthly Notices.
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