Explosion & # 39; supernova ġiganteska have led to mass extinction to prehistoric creatures living in the world's oceans some 2.6 million years ago, according to new research published in Astrobiology.
marine animals such as Megalodon, a shark & # 39; appreciation & # 39; about 10.5 meters (34 feet) long and b & # 39; huge xangoli filled with & # 39; signals sharp and piercing, disappeared in & # 39; blow during the late Pliocene. Around the same time, scientists from the University & # 39; Illinois and the Federal University & # 39; Sao Carlos noted the peak in isotope iron 60 in & # 39; old sea countries.
"Since the mid nineties, people said," Hey, look iron 60. It is because telltale m & # 39; there is no other way to arrive at this World but a supernova. "Because the iron-60 is radioactive, though it was formed with the World, would be long now. So, was felt on us", explained Adrian Melott, main author of the paper and professor of physics and astronomy in University & # 39; Kansas.
"There is some debate about whether there was only supernova one really near and chain them. I kind of & # 39; for a combo of both – great chain & # 39; one was exceptionally strong and close. If you look at residue iron 60, there is a huge boost & # 39; 2.6 million years ago, but a clear surplus spilled back 10 million years. "
The team believes that supernova located 150 light years away set & # 39; & # 39 chain; explosions & # 39; supernovae and covered in the World & # 39; & # 39 memja of; deadly cosmic radiation. This was amplified, Melott said, because the Solar System is right at the edge of & # 39; the interstellar medium area called Local Bubble.
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Local Bubble extends about 300 light years and contains two major dust clouds and gas: Local Interstellar Cloud and G-Cloud. "It's basically very hot, gas b & # 39; very low density – almost all gas clouds were swept by. The best way to manufacture & # 39; bubble like that is a whole bunch of & # 39; bumps a & # 39; supernovae larger and larger, and it seems that fits well with the idea of & # 39; chain, "said Melott.
Since supernovae left the cosmic rays, these rays & # 39; energetic particle repeatedly successful of the partners to create a "bathroom with kosmiku radius" could & # 39; 10.000 ran up 100,000 years old, he proposes. Some of that radiation such as muon beam kożmiku nxfu on the World, and over time it could & # 39; led to genetic mutations and cancers.
Muon pass over the World all the time, but over the top iron – 60 times the number would be large enough to cause health problems for animal life. The researchers estimated that the cancer rate increased by & # 39; about 50 percent for large animals were human size, and rising further to larger creatures. Animals like Mgododon were absorbing enough radiation to develop cancer and die prematurely.
"Really there was no good explanation for sea megafaunal extinction", said Melott. "It can & # 39; is one. It is this paradigm shift – we know something happened and when it happened, so first we really dig and look things b & # 39; defined way. Now we can rely really about x & # 39; Are the effects of radiation b & # 39; that it was not possible before. "®