The mystery of the space around our solar system is due to the evidence of supernovae found in the deep sea silt.
The study, led by ANU professor of nuclear physics Anton and Wall Lanner, shows that the earth has been traveling through a cloud of obscure radioactive dust for the last 33,000 years.
“These clouds may be remnants of previous supernova eruptions, a powerful and super bright eruption of the star,” said Professor W. Wall Lanner.
Professor W. Wall Lanner conducted research at the ANU Heavy Ion Cele Accelerator Facility (HIAF). He also holds joint positions at Helmholtz-Zentrum Dresden-Rosendorf (HZDR) and Technical University Dresden (TUD) in Germany.
Using the extreme sensitivity of HIAF’s mass spectrometer, the researchers discovered many deep sea sediments from two different locations. They found clear traces of the isotope Iron-60, which form when stars die in supernova explosions.
Iron-60 is radioactive and decomposes completely in 15 million years, which means that any Iron-60 found on Earth must have formed compared to the rest of the 6.6-billion-year-old Earth and arrived here from a nearby supernova before settling. Should be. On the sea floor.
Professor W. Wallner first found traces of the Iron-Trak about 4.6 million years ago, and probably another about a million million years ago, suggesting that the Earth passed through clouds falling from a nearby supernova.
For the last several thousand years, the solar system has been passing through a cloud of gases and dust, known as the Local International Cloud (LIC), whose origin is unclear. If this cloud had originated from a supernova during the last few million years, it would have contained Iron-60, and so the team decided to find the most recent silt to find it.
Sure enough, Iron-60 in the silt was at a very low level – equivalent to the level of radioactivity in space compared to Earth’s natural background level – and the distribution of Earth’s most recent travel match with Iron-60 through the local stellar cloud. But Iron-60 expanded further back and it spread over a period of 33,000 years.
The lack of consistency with the timing of the solar system in the current local interstellar cloud raises more questions than its answers. First, if the cloud were not formed by a supernova, where did it come from? And second, why is Iron-60 evenly distributed throughout space?
There are some papers that show iron-60 trapped in dust particles indicating that the interstitial medium is bouncing around it, Professor Wolner said. “So the violation of Iron-60 can also be caused by old supernova explosions and what we measure is a kind of echo. More data is needed to resolve these details. ”
The findings have been published in the journal P.N.A.S..
Reference: “60AA. Wolner, j. Fij, L. K. Field, M.B. Frohlich, R. Golzer, M.A.C. Hotkis, d. Cole, g. Lackenby, m. Martschini, s. By late Pleistocene and Holocene, Fay phase during the past of supernova activity. Marchel, s. Panzkov, s. Pavetich, g. Rugel and SG Tim, 24 August Gust 2020, Proceedings of the National Academy of Sciences.
DOI: 10.1073 / PNAS.1916769117
Scientists from ANU, the Australian Australian Atomic Science and Technology Association, HZDR, the University of Vienna and TU Berlin were involved in the study.