According to numerous studies, after the birth of the universe, it was filled with only light substances - hydrogen and helium. All other chemical elements can occur only in the process of burning stars. This means that our planet (and we) consists of a substance formed in the depths of the prehistoric stars and ejected once in supernova explosions.
According to scientists, each type II supernova produces active isotope of aluminum (26Al) about 0.0001 solar masses. The disintegration of the isotope poses hard radiation, which occurred a long time, and its intensity is calculated that the content of this isotope in the Galaxy - less than three solar masses. This means that the type II supernovae should explode in the Galaxy, on average, twice per century, which was not observed. Perhaps, in the last century, many such blasts fail to notice (occurring at the clouds of space dust). Therefore, the majority of supernovae observed in other galaxies. Deep sky surveys on automatic cameras connected to telescopes, astronomers now make it possible to open more than 300 outbreaks each year. In any event, a supernova star is high time to explode ...
According to one hypothesis of scientists, space dust cloud resulting from the outbreak of a supernova, could stay in space for about two or three billion years!