Astronomers have known for some time that nearby supernovae had a profound effect on the development of the earth. For the beginning it is assumed that earth deposits of gold, platinum and other heavy metals have been distributed to earth by old supernovae. The explosions of the gamma rays released in the process can also significantly influence the lifespan, reduce nitrogen and oxygen in the upper atmosphere, reduce the ozone layer and cause harmful mirrors of the ultraviolet radiation to reach the surface. In view of the number of almost the ground of supernovae, which has occurred 4.5 billion years ago, these events probably influenced the development of life.
In a new paper from a team of astronomers at the University of California Santa Cruz (UCSC), a nearby supernova may have influenced the development of life on earth. According to its findings, the earth was deleted from a nearby supernova about 2.5 million years ago by radiation. This radiation boost was powerful enough to break the DNA of the living beings in Tanganyika -See, the deepest water body in Africa. This event, you argue, could be associated with an explosion of the number of viruses that have occurred in the region.
The study was headed by Caitlyn Nojiri, a graduate from the USCS department for astronomy and astrophysics. She was accompanied by Enrico Ramirez-Ruiz, a USCS professor of astronomy and astrophysics, and Noémie Globus, postdoctoral fellow at USCS and member of the Kavli Institute for Partche Astrophysics and Cosmology at Stanford University and the Astrophysical Big Big Laboratory. The paper that describes its results was published on January 15 in the magazine Astrophysical Journal Letters.
The picture of Lake Tanganyika was taken over in June 1985. Credit: NASA
For her study, the team rehearsals from the Iron-60 from the sea floor of Lake Tanganyika, the 645 km long lake in the Great Rift Valley Africa, Burundi, Tanzania, Zambia, and the Democratic Republic of Congo borders. This radioactive iron isotope of iron is produced by supernovae and is extremely rare on earth. They received age estimates based on how much rehearsals had already divided into non -radioactive forms. This resulted in two separate age groups for rehearsals, about 2.5 million years and the other 6.5 million years.
The next step was to track the origin of the iron isotopes, which they attributed to the backtrack of the sun movements around the middle of the Milky Way. About 6.5 million years ago, our solar system went through the local bladder, a region with a lower density in the interstellar medium (ISM) of the Orion arm in a milky way. As the solar system penetrated into the stardust-rich outer of the bladder, the earth was sown with the older traces of iron-60. A neighboring star Supernova went 2 and 3 million years ago and set the earth with the younger traces of iron-60.
In order to confirm this theory, Nojiri and her colleagues carried out a simulation of an almost earth -end supernova, which pointed out that it had bombed the earth with cosmic rays for 100,000 years after the explosion. This model matched a previously recorded radiation tip that hit the earth around this time. In view of the intensity of the radiation, this increased the possibility that it was sufficient to grab DNA strands in two halves. In the meantime, the authors came up with an examination of the variety of virus in one of the Rift Valley Lakes Africa and saw a possible connection. Nojiri said in a UCSC press release:
“It is really cool to find ways to influence our life or the habitability of the planet. The Iron-60 is a way to trace back when the supernovae appeared. Of two to three million years, we believe that a supernova nearby has happened. We saw from other papers that radiation can damage DNA. This could be an acceleration for evolutionary changes or mutations in cells. We cannot say that they are connected, but they have a similar time frame. We found it interesting that the viruses gave increased diversification. “
The main author Caitlyn Nojiri is now applying for the graduate school and hopes to have a Ph.D. in astrophysics. Credit: UCSC
Shortly after her newspaper was released, Nojiri was the first UCSC student who stated a seminar in the Center for Cosmology and Astropartic Physics (CCAPP) in the state of Ohio. Nojiri did not start as an astronomer at first, but finally came at the UCSC, where Prof. Ramirez-Ruiz encouraged her to apply for the program of the University of California Leadership as part of the Advanced Degrees (UC Leads). This program is intended to identify students with different backgrounds who have the potential to be successful in Stem.
She also took part in the Lamat program (“Star” in Maya), which was founded by Ramirez-Ruiz to teach students with great ability and non-traditional backgrounds, as was researched in astronomy. Because of her experience with these programs, Nojiri has decided to apply for a graduate school and become astrophysicists.
“People from different areas of life bring different perspectives to science and can solve problems in very different ways,” said Ramirez-Ruiz. “This is an example of the beauty of having different perspectives in physics and having these voices.”
Further reading: UC Santa Cruz, The Astrophysical Journal
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