The largest predator on Earth has died out as a result of a supernova explosion
Our planet has experienced many global events since the Pliocene period gave way to the Pleistocene 2.6 million years ago. The general temperature of the Earth has decreased, Africa has dried up, ice caps have formed at the poles, and a wave of repeated glaciation swept across the continents - in other words, ice ages.
Tyrants of the seas
Climatic changes entailed the disappearance of a number of species of marine fauna, among which was the largest predator ever existing - megalodon. This giant prehistoric shark grew to 18 meters in length: its teeth were the size of the forearm of an adult male, and the strength of bites reached 18, 000 kg / cm2!
A serious reduction in species diversity would undoubtedly affect the diet of sharks, consisting of large game - whales, seals and other animals. In addition, crushing seas could simply isolate them from each other and reduce habitat. Nevertheless, according to some reports, the megalodon population during the Pliocene was so high that much more global and destructive changes would be required for their complete extinction. So what really happened?
A new study published in Astrobiology provides some compelling evidence linking the disappearance of megalodone with another catastrophic event that happened 2.6 million years ago. Led by Adrian Melott, Emeritus Professor of Physics and Astronomy at the University of Kansas, a group of scientists suggested that the whole blame could be ... a supernova, or even a whole group of such stars. Sediment samples taken from the seabed unexpectedly showed a huge burst of radioactive particles - they appeared at about the same time that huge predators died out.
Recall that when a massive star uses up most of its constituent hydrogen and helium, it explodes, spreading radiation streams in space. If this happens close enough (at a distance of up to 160 light-years from Earth), then high-energy cosmic rays penetrate the atmosphere of the planet. “They tear molecules apart, they can even tear electrons from the atom, and all these processes take place right down to the ground, ” Melott explains. According to the scientist, the radiation background of the planet during such events can increase three times.
Typical markers of the fact that such incidents occurred in the past are isotopes - for example, such as iron-60. In addition, the interaction of stellar radiation with the atmosphere produces subatomic particles - muons. They are 200 times heavier than electrons and can penetrate hundreds of meters of solid rock. In living cells, high concentrations of muons provoke the development of cancer.
After a supernova explosion, all creatures on Earth were exposed to 20 times the “normal” muon load. The larger the creature - the, respectively, increased the probability of mutations. What can we say about the megalodon, which, being the largest creature on Earth, has become a real magnet for muons. At the same time, another global event happened - the Earth’s magnetic poles turned upside down. Magnetic north and south survived the inversion, and in the process, they left the planet defenseless, because it is usually the magnetic fields that deflect the flux of cosmic radiation. All of this combined exposed the inhabitants of land and especially the sea to unprecedented radiation exposure.Do you like the article?
The most interesting news from the world of science: fresh discoveries, photos and incredible facts in your mail. OK I agree to the rules of the site Thank you. We have sent a confirmation email to your email.