The light of an exploding star can offer an impressive spectacle, as it is brighter than a full moon. However, it can also pave the way for disaster according to a new study.
A team of researchers argues that the intense cosmic rays which are released by nearby supernovae could have been the cause of at least one mass extinction event, with the presence of select isotopes in rocks serving as proof, which makes the scenario a viable one.
The new study explored the boundary between the Devonian and Carboniferous periods. Rocks that formed during the boundary timeline contain an impressive amount of plant spores, which seem to have been burnt by intense ultraviolet light, a trait that signals the presence of an ozone-depletion event.
Massive volcanic eruptions and global warming can affect the ozone layers, but there are no signs of such large-scale events within the relevant timeframe. One or more supernova explosions that took place at a distance of 65 million light-years away from Earth could be tied to the deterioration of the ozone layer.
A supernova explosion releases cosmic radiation in two stages. The first release takes place when the star explodes, emitting a large amount of UV, Gamma, and X-rays, which are headed towards Earth. During the second stage, supernova fragments are pushed across the solar system, with the accelerated cosmic rays dealing more damage.
Information gathered from fossils infers the existence of a 300,000 years-long decline in biodiversity, which paves the way for the Devonian-Carboniferous max extinction, several supernovas may have damaged the ozone layer. The presence of two radioactive isotopes that do not appear naturally on Earth would conform to the theory, and the team will start the search for geological proof in the future.
A paper has been published in a scientific journal.