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.
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. 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…