The scientists said the planet may have been influenced by the strongest known in the universe explosion - a gamma-ray burst - during the eighteenth century.
The researchers found in 2012 is evidence to suggest that our planet was wounded in the explosion of radioactivity occurred during the Middle Ages, but it is still a cause controversy about what cosmic event, which probably caused the explosion.
According to a recent study that it may have resulted from the two black holes or merger of stars in our galaxy.
Such an explosion may result in the release of huge amounts of energy.
The study was published in the journal (monthly observations of the Royal Astronomical Society).
A snapshot of nature
In the past year a team of scientists found on some old cedar trees in Japan contain extraordinary levels of radiation carbon known as carbon-14.
In Antarctica, there was a sharp rise in the levels of substance beryllium -10 in the ice.
These isotopes are made when intense radiation collides with atoms in the upper atmosphere, which is likely that there is an explosion of energy hit our planet from space.
Scientists using data tree rings and ice samples to determine that it occurred between 774 and 775 AD, is that the cause of the incident is still a mystery.
And deployment of a team of physicists Americans finally search is likely to be a huge solar explosion on an exceptional generation has caused this burst of energy. But others in the scientific community objected to this, because they do not believe that the energy generated consistent with the levels of carbon -14 and beryllium -10.
The last team of German researchers another explanation to the effect that a huge explosion happened in the Milky Way.
And said Ralph Njohauser, a supervisor on the research at the Institute of Space Physics at the University of Jena "We are short blasts Spectra of gamma-ray in order to determine whether it was consistent with the rate of production of carbon -14 and beryllium -10 that we've seen, and we have reached it's completely identical."
The Njohauser added that "gamma-ray bursts are highly explosive incidents and full of energy, so energy Astenbtna What is the distance taking into account the observed energy."
"It was our conclusion is that it is at a distance of between 3,000 to 12,000 light-years away, which is located within our galaxy."
In spite of the fact that the event may seem exciting, the ancestors in the Middle Ages did not notice anything.
If gamma-ray burst has occurred on this distance, it is our atmosphere would have sucked due to radiation leaves only the isotope effects on the body made its way eventually to the trees and ice. Scientists believe that the event did not lead to any visible light emission.
Rare events
Suggest deep space observation that gamma-ray bursts is rare. There is a belief that they occur at most every 10 thousand in each galaxy, and at least every million in each galaxy.
The Njohauser said he is not likely to see another planet explosion soon, but if it happened, this time it will be a significant impact.
If the recurrence of a cosmic explosion at the same distance as in the eighth century will hit the satellite.
In commenting on the research said Adrian Milot professor at the University of Kansas that despite the belief that an explosion short gamma-ray is the conclusion of the question, the research conducted by the team suggests that the most likely cause might be an explosion sun, depending on the views Anjum similar to the sun in our galaxy .
He Milot that "event for Proton sun or splash of gamma rays are two explanations possible routes, but based on as much as is available to our knowledge about the universe, the interpretation of an explosion splash of gamma rays are less likely about 10 thousand times to be real in that period."
