Supernova Explosion May Have Caused The Massive Extinction On Earth, Experts Claim

Experts claim that a supernova explosion may have been one of the many reasons for a minor mass extinction on Earth. The explosion that happened about 2.59 million years ago was estimated to have taken place millions of miles away.

According to hngn.com, researchers explained that the cosmic rays that had fast-moving, charged particles were probably released by the supernova extinction. The cosmic rays influenced certain changes in the Earth's climate that l possibly led to mass extinction. Experts also said that this happened sometime between the end of Pliocene epoch and the start of the Pleistocene.

In an article by Popular Science, it said that it's generally accepted there will be stars which had gone supernova around 300 light years from Earth in the past million years. Two recent studies showed evidence for these supernovae. One research claimed that researchers were able to trace the amount of iron-60, a radioactive form of iron, in deep-crusts.  Iron-60 was thrown in to space by these supernovae or by winds from large stars, and having it present somewhere meant that a star exploded nearby. Scientists said they found two penetration of iron-60, one was about 1.5-3.2 million years ago and another was 6.5-8.7 million years ago.

Meanwhile, another group of researchers calculated the possible trajectory of these supernovae and discovered that the stars were at least nine times the size of the Earth's sun. These researchers also added that the supernovae could have exploded 300 light years away from Earth.

Scientists of the new study were puzzled about how these recent supernovae might have affected life on Earth and its atmosphere. To cause a remarkably catastrophic extinction, a supernova should be about 26 light-years from Earth. "This event is not close enough to have precipitated a major mass extinction, but may have had noticeable effects," wrote the researchers, who recently published the findings in Astrophysical Journal Letters, space.com reported.

These results surprised the research team. The team did a simulation and it suggest that a supernova claimed by other researchers to have caused a mass extinction "bathed the night sky in blue light so bright that it disrupted animals' sleep patterns for weeks." More importantly, the radiation surge most likely hit organisms on land and the shallow parts of the ocean.

"The big thing turns out to be the cosmic rays," study co-author Adrian Melott of the University of Kansas said. "The really high-energy ones are pretty rare. They get increased by quite a lot here - for a few hundred to thousands of years, by a factor of a few hundred. The high-energy cosmic rays are the ones that can penetrate the atmosphere. They tear up molecules. They can rip electrons off atoms, and that goes on right down to the ground level. Normally, that happens only at high altitude."

The end result was likely a tripling of the overall radiation dose at ground level, the researchers found. This may have been enough to increase cancer and mutation rates, "but not enormously," Melott continued. "Still, if you increased the mutation rate, you might speed up evolution."