Recent research astrophysicists argue that life on Earth can break the gamma-ray bursts, resulting from the collapse of stars. This theory explains not only the numerous mass extinctions on our planet, including dinosaurs, but even then, why do we still have not heard signals from the brothers on reason.
For a long time, the main threat from outer space, asteroids and comets were considered. Governments of major world powers for some time even began to develop programs to prevent collisions with the Earth large celestial bodies. However, staff at the University of Kansas Uoshbernskogo recently presented a report saying that the death of all living things worth waiting for from outer space, and protect themselves from it is almost impossible.
Collision of stars and supernova explosions, and then place in the universe, including the Galaxy, produce huge emissions of gamma radiation. The waves, which penetrate with the far corners of the galaxy, able to fully deplete the ozone layer in the stratosphere, and open the way lethal ultraviolet radiation, which will destroy all life on Earth. This has already happened many times, scientists believe.
"We found that a certain type of gamma rays — short gamma-ray bursts — have a more significant impact than the long gamma-ray bursts — said one of the study's authors, Brian Thomas. — The thing that is important, not the length of the radiation, and the amount of radiation ".
As noted Livescience.com, gamma-ray bursts are divided into two types. "Long" are characterized by bright flashes that can be seen for some time. "Short" for less than a second, but recovered with a huge amount of radiation. These bursts occur during the collision of dense neutron stars, supernova explosions, or when the heavenly bodies are killed in the mouth of a black hole.
The main effect of this radiation, says Thomas, is the effect on the free oxygen and nitrogen atoms, which recombine into dangerous ozone nitrogen oxides. Thus, in the case of stellar explosion in the Milky Way galaxy, these long-lived molecules will destroy the ozone layer of our planet for as long as it does not lose its only protection from fatal radiation.
The researchers were able to calculate that in the Galaxy such collisions occur at a frequency of about once every 100 million years. This means that the Earth has not once suffered the consequences of similar disasters. Now scientists have evidence to establish temporal relationship periods of mass extinction, and the cosmic gamma-ray bursts.
Astronomical data there is unlikely to help, as the picture of the galaxy varies significantly every million years, and catch sight of the ancient echoes of explosions is almost impossible. However, the search for proof of his theory, researchers intend to find not in space and on Earth. In particular, scientists believe, the study of the isotope iron-60 in fossils from different periods can give them comprehensive data on radiation incidents that could lead to a mass extinction.
"I work with some paleontologists and we try together to find a correlation between radiation bursts and extinction," — said Thomas. He noted that while paleontologists are skeptical of this theory, but astrophysicists it seems very plausible.
Assumption that gamma-ray bursts caused megavzryvami at the other end of the galaxy, can be dangerous to life on our planet have already been made. However, the first astrophysics not looked into the future and into the past, trying to find a solution of the mystery in the history of the Earth.