When scientists study stunning cosmic explosions, they are usually events that occurred very long ago, typically hundreds of millions or billions of years ago, in extremely distant parts of the universe. We can marvel at their destructive power, but the effects of these events on earthly life are usually minimal.
But the relatively recent discovery of certain types of isotopes on the ocean floor suggests that at least one of these events took place relatively close to our home. And it probably didn’t happen that long ago – a kilonova apparently exploded near the Solar System about 3.5 million years ago. At that time, the Earth was already inhabited by australopithecines.
Evidence of a kilonova
How can such a thing be found out? Scientists recently detected an unusual pair of isotopes in marine sediments of this age: iron-60 a plutonium-244. Iron-60 isotopes can also be produced in supernova explosions, but the combination with plutonium-244 suggests that in this case it was something special.
As they state in the so far unreviewed article Leonardo Chiesa from the University of Trento and his colleagues, the isotopes discovered and their ratio can best be explained as traces of a kilonova explosion after the collision of two neutron stars.
Earlier analyzes had ruled out this possibility, but Chies’ team included a number of other factors in their considerations, including the course of gravitational collapse during a kilonova and the bombardment of matter with loads of neutrinos. The mechanism of the formation of a kilonova is still not completely clear, but scientists assume that the remnant of the kilonova is a black hole. If Chiesa et al. truth, we should count on the existence of a black hole located at a distance of about 500 to 600 light years from the Solar System.
2023-12-16 08:05:47
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