In the samples of the oceanic bark, scientists have found isotopes of plutonium and iron, which are not found on earthly conditions. The article is published in the journal Science.
According to the authors of the discovery, this suggests that the surfaces of the Earth periodically reach the streams of the substance thrown in the explosions of supernovae or the fusion of neutron stars.
It is believed that the kernels of all chemical elements that are heavier than iron are formed in a star medium as a result of a nuclear process of consistent neutron capture and creating increasingly heavy nuclei. In total, about half of heavy nuclides is formed slowly as a by-product of sustainable star synthesis. At the same time, another half, including all actinoids, arise in the process of rapid neutron capture.
Scientists managed to reproduce the process of rapid neutron capture in laboratory conditions, however, it is not established as it occurs in space. Now there are two hypotheses on this subject: with the explosions of some types of supernova and fusion of neutron stars.
The authors believe that their discovery allows you to look at the astrophysical origin of heavy chemical elements in a new way.
In March in the sample of the soil with an asteroid (25143) of the Iokava, delivered by the probe “Hayabus”, traces of water and extraterrestrial organic substances were detected. The organic substance is represented by nanocrystalline graphite and polycyclic aromatic hydrocarbons with high deuterium ratios to hydrogen and nitrogen-15 to nitrogen-14.