Last year, Japanese scientists have found evidence that in the 775 ad on Earth was unexpected burst of radiation of high intensity. This explosion has had the energy, about 10 000 times the energy of the atomic bomb dropped on Hiroshima. It is established that in orbit around the planet disaster, which by some reason was not noticed 350 million people who lived at that time on Earth: no historical records do not mention about the strange events of the year.

At the same time, the traces of this event can be identified by the concentration of radioactive carbon contained in the annual rings of some of the oldest trees on the planet. Key radioactive isotope of carbon, carbon-14, formed when energy particles enter the Earth's atmosphere and collide with atoms of nitrogen. Because trees absorb carbon-14 and its stable relative carbon-12, it provides scientists way of measuring the amount of high-energy particles in the atmosphere of our planet in a particular year. Having analyzed last year two ancient Japanese cedar, scientists found that the amount of carbon-14 contained in their annual rings for 775 year of our era, was much more than in other years.

Fluctuations in the concentration of carbon-14 is normal: it grows and shrinks with 11-year cycle with increased and reduced solar activity. However, during the whole 3000-year period, this figure was never so high as in the 775 year. So what could cause such a serious surge of radioactivity and a significant increase in the number of energetic particles, which led to the growth of carbon-14 in the atmosphere? At first glance, there are two possible explanations: the radiation was the result of very strong explosion on the sun, or the explosion of a nearby star.

The scientists rejected the version with solar explosion for two reasons. First, you need to do this magnitude had to call an unprecedented intensity of the Northern lights, which were recorded. Secondly, more importantly, the explosion of such power could destroy the Earth's ozone layer, exposing all life on the planet strongest radiation that would lead to the destruction of all life.

Let's move on to the second version. Nearby supernova could send gamma radiation in all directions. These rays could result in our atmosphere of high-energy particles, which in turn would have triggered the formation of the carbon-14, traces of which were found in the Japanese cedars. However, to send gamma-rays such force, the supernova was to be bigger and brighter than any other similar celestial bodies, documented at the time. However, no record of existence in the 775 year such stars not.

Moreover, even if people haven't noticed the explosion of the star, its remains are still would have to remain in space, radiating light, which might notice telescopes. Scientists have identified 11 such splinters in our galaxy, but none of them has the right age to fit into the theory of the explosion 775 year. When it was found that neither the explosion on the sun, nor the destruction of a supernova can't be the explanation for the revealed anomalies with carbon-14, scientists have published the findings of his research and has accepted that this phenomenon remained a mystery.

However, recently a group of researchers from Germany made a pretty good theory. In their opinion, the reason of such phenomenon could become the momentary gamma radiation caused by the collision of two nearby neutron stars. Although the collision and was a significant event (imagine two boulder with a width of about 20 kilometers, each of which has a weight of the Sun, from the Earth it could be observed only during the day. This can explain the fact that the clash was never documented. Scientists have identified five neutron stars, which could cause such a burst of radiation. Now their task is to analyse these candidates and to establish the exact cause of the mysterious phenomenon.

Popsci.com