A new hypothesis emerges from the study of a supernova remnant identified by scientists as 1993J. Scientists now think that the explosion might have caused the mass extinction on Earth, more than 2.59 million years ago.
The supernova explosion might have blasted cosmic rays that would have reached our planet and created a major extinction that occurred between the Pliocene and the Pleistocene epochs.
The authors of the study explain that the explosion could have created the desert in Africa and made forests turn into savannas. Another mystery that could have been explained by the cosmic rays is that of the glaciations, recurring ice ages that at this moment have no scientific justification.
The Pliocene Supernova Explosion
The computer simulation was conducted by the researchers from the Washburn University in Kansas. The authors tried to observe how a supernova explosion might have affected the climate and the biosphere on Earth.
As the event happened relatively recent in the history of the Earth, the scientists only took into consideration supernovas that are at 300 light-years away from our planet.
The scientists initially believed that such a distance to Earth would have protected our world from the cosmic rays of the explosion. However, the results show that radiation could have reached our planet and the organisms on land.
Another factor was the blue light that the blast would have left in the sky. The scientists believe the light could have lasted for weeks, which could have disturbed the animals’ sleep patterns.
The Cosmic Rays’ Effects
The high-energy cosmic rays are so powerful that they can penetrate into the atmosphere, tear up molecules, and reach the ground level. After reaching the surface of our planet, the immense radiation could have resulted in an increase of cancer and mutation rates. Another effect might have been a speeding of the evolution.
As for the climate, the scientists believe that the cosmic rays forced atoms and molecules to gain a negative or a positive charge. The ionization process is supposed to have lasted more than 1,000 years, and it is possible it might have triggered the climate change and brought the series of ice ages.
The present study is the first to demonstrate that a supernova explosion might have had such catastrophic effects on Earth. The earlier simulations implied the fact that a supernova would need to be very close to our planet in order to affect the climate and the biosphere.
While the previous study showed the critical distance would have been 25 light-years, the present study proves that even a distant supernova explosion may have had a huge impact on our planet.
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