

(Newser)
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A mass extinction event that struck Earth 359 million years ago continue to has researchers scratching their heads. Was it volcano eruptions? Meteorites? Gamma-ray bursts? A new paper seems to be at a further possible culprit: exploding stars. Scientists at the College of Illinois argue that proof hidden in rocks coincides with the influence of at the very least a person supernova 65 light-weight-several years from Earth in the Late Devonian period of time, Futurism reviews. Analyzing ancient plant spores in rocks, they located signals of significant ultraviolet light-weight sunburn—just what you would assume from extended-expression ozone depletion in the ambiance. “Massive-scale volcanism and worldwide warming can wipe out the ozone layer, as well, but evidence for all those is inconclusive for the time interval in query,” lead writer Brian Fields states in a statement.

Now his crew is seeking what Fields calls “the smoking cigarettes guns of a nearby supernova”: the radioactive isotopes samarium-146 and plutonium-244 in fossils and rocks deposited for the duration of the extinction. “Neither of these isotopes occurs in a natural way on Earth currently, and the only way they can get here is by using cosmic explosions,” suggests co-author Zhenghai Liu. Appealing side notice: The staff considers a number of blasts a likelihood due to the fact big stars generally exist in clusters and can detonate if triggered by a supernova in the team, Forbes notes. But Fields sees a even larger message in all this: “Life on Earth does not exist in isolation,” he suggests. “We are citizens of a much larger cosmos, and the cosmos intervenes in our lives—often imperceptibly, but from time to time ferociously.” (Examine much more mass extinction stories.)

