Scientists discover “smoking gun” evidence of a recent supernova close to Earth.
If you needed any more shocking information, we now know that a supernova erupted quite recently, some 2.5 million years ago, extremely close to Earth. Although it might seem like a long time ago, that was only yesterday in the history of our 4.5 billion-year-old world.
Supernovas are extraordinarily brilliant explosions of dying stars. According to a recent analysis, a burst 4.5 million light-years away might produce up to 10 times as much energy as the sun can produce in its whole lifespan. Additionally, it disperses a vast quantity of substances throughout the cosmos. Recent research examined this spread and discovered that concentrations of specific elements indicate to a supernova that occurred only 2.5 million years ago close to Earth.
Mn-53, a radioisotope created by supernovas, was discovered in unusually high concentrations by the researchers. Earlier investigations searched for these residues in quantities of the iron isotope Fe-60.
The team of researchers, lead by Dr. Gunther Korschinek of the Technical University of Munich, concentrated on ferromanganese crusts for their investigation. These marine sediments, which are primarily made of iron and manganese oxides, protrude out into the water over time. They are hence excellent chemists of the water’s compounds. The scientists discovered Mn-53 in addition to Fe-60 when studying these ferromanganese crusts from Pacific Ocean sites. The samples were collected at depths ranging from 1,589 metres (5,213 feet) to 5,120 metres (3.18 miles).
What do the researchers learn from the presence of Fe-60? Its 2.6 million-year half-life suggests that it was produced in a nearby supernova explosion very recently. If not, nickel would have deteriorated into 60Fe.
What impact did a supernova have on Earth if one occurred within the very recent past?
The isotope’s putative formation in dying asymptotic giant branch (AGB) stars is another theory for its existence. However, the scientists believe that the existence of 53Mn, which cannot be formed by such stars, strongly suggests that supernovae are the source.
Scientists discover “smoking gun” evidence of a recent supernova close to Earth.
Dr. Korschinek stated in a press release that the elevated manganese-53 concentrations serve as the “smoking gun” and the conclusive evidence that this supernova actually did occur.
The Mn-53 atoms were found by the researchers using accelerator mass spectrometry in the crust, which resembles a firm chocolate cake.
Korschinek stated, “This is investigative ultra-trace analysis. We are only discussing a few atoms here. Accelerator mass spectrometry is so sensitive that it even allows us to determine from our observations that the star that exploded must have had about 11 to 25 times the size of the sun,” he continued, adding that the technology is also highly useful in determining the sizes of the original stars.
What impact did a supernova have on Earth if one occurred within the very recent past? The researchers believe it probably triggered cosmic ray showers and had an impact on the climate. The Pliocene demise of the marine megafauna may have also been a result of it.
