A supernova outbreak is a signIt is the end of the life cycle of a massive star, which is accompanied by a sharp increase in its brightness. However, it was thanks to supernovae that all life on Earth appeared, including us and you. So, the atoms in your right hand originated in the bowels of the long-dead star, and the atoms in your left hand - in the bowels of the other. However, despite all the poetry and beauty of this phenomenon, a supernova explosion located close to the Earth can cause a disaster. This is exactly what happened about 2.6 million years ago - the explosion of one of these stars illuminated the sky of our planet from a distance of about 150 light years. Several hundred years later, when the new star had already disappeared from the firmament, cosmic rays reached the Earth. Recently, scientists have found that this cosmic phenomenon is associated with the mass extinction of animals that roamed at the time on the surface of our planet. The study is published in the journal Astrobiology.
According to a research press release recentlyThe documented “marine megafauna extinction” coincides with the arrival of a potentially fatal radiation flux coming from a supernova explosion near the Earth. This outbreak, scientists believe, has led to the fact that about 36% of the species (including Megalodon) that live in coastal waters have become extinct. Researchers believe that the killer radiation reached the Earth in the form of cosmic rays, consisting of rapidly moving muons - elementary particles with a negative charge, the mass of which is several hundred times the mass of an electron.
Megalodon - a species of extinct sharks that we mentioned in one of our materials. A muons Are unstable elementary particles with a negative electric charge
Based on the speed at which muons hit the Earthas a result of a supernova explosion, scientists calculated that if this event took place in our time, then the risk of developing cancer in representatives of Homo Sapiens would increase by about 50%. And since high-energy muons can penetrate deeply into the water, they could have had a fatal effect on marine life, causing them to die out massively. Discover cites the authors of the study that muons are a couple of hundred times more massive than an electron and penetrate everywhere. Today, many muons pass through us without causing any harm, but about one fifth of the dose of radiation received by humans falls on them. But why did scientists decide that the cause of the mass extinction was muons?
Read more articles about the mass extinctions of wildlife that have occurred on Earth on our channel in Yandex.Zen
How is a supernova explosion related to the mass extinction of wildlife?
Supernova explosion traces discovereddeposits of the iron-60 isotope - a radioactive isotope of iron, which, if it had been included in the Earth at the time of its formation, would have decayed long ago. And researchers recently discovered traces of isotope-60 in samples of the earth's crust collected in the Pacific, Atlantic and Indian oceans. Explosion of stars can be the only source of deposits of this isotope in the bowels of our planet. But where did the supernova come so close to Earth?
As the authors of the article write, the sun is insidewhat astronomers call a local or local bubble is a relatively empty region of interstellar space. In total, a local bubble is an area 300 light-years wide that is filled with hot gas and limited to cold. Researchers believe that such bubbles, and there are many of them in our region of the galaxy, appeared as a result of explosions of supernova stars, the energy from which can sweep everything in its path, and what remains is heated up to form a bubble.
However, scientists do not exclude that the local bubbleappeared as a result of the explosion of several supernovae, which also caused the deposition of the iron-60 isotope in the bowels of our planet. Moreover, it is possible that a local bubble could increase the number of radioactive rays - its boundaries could reflect the rays, creating a kind of "bath of cosmic rays."
What do you think, if you and I had a chance to swim in such a radioactive bath, what would it lead to? Share your answer in the comments and with the participants of our Telegram chat
In general, the results of the study showedthat a supernova that erupted 2.6 million years ago may be due to the extinction of marine megafauna at the border of the Pliocene and Pleistocene. At the same time, the organisms that lived in coastal waters received the largest share of radiation, since with increasing depth, the damage of muons decreased.