In the Past, a Supernova Explosion Might Have Triggered a Mass Extinction
As the Late Devonian Era stretched, many creatures went extinct in one of the largest mass extinctions our world has witnessed about 359 million years ago. Many deaths for which the culprit is responsible are said to be non-local, such that they may not even be from our Solar System. A study conducted by astrophysicist Brian Fields suggests that this great life-extinguisher is a distant and utterly alien event – a dying star many light-years away from our planet.
It is sometimes thought that mass extinctions, such as those in the Late Devonian, were triggered mainly by terrestrial causes, such as a volcanic eruption that drowned the planet in life. Or that intruder and the deadly guest could be an asteroid collision of the kind that consumed the lineage of the dinosaurs. Death from outer space can come from very distant places.
“We are inhabitants of a larger cosmos and the cosmos interferes with our lives. Often vaguely, but sometimes brutally. “
In their new study, Fields and his team have discovered the possibility that the dramatic drop in ozone levels coinciding with the Late Devonian Period may not be the result of volcanism or part of global warming. Instead, they suggested that the biodiversity crisis could be caused by astrophysical sources, presumably by the radiation effects of one or more supernovae.
Supernovas are the source of ionizing photons
The idea that supernovas triggered mass extinctions dates back to the 1950s. In the recent past, researchers have been discussing the estimated “kill range” of these explosive events. These estimates range from 25 to 50 million light-years. However, in their new estimates Fields and co-authors claim that stars exploding further away could also have detrimental effects on life on Earth.
“Supernovae are the source of ionizing photons: UV, X, and Gamma rays. “He explains.
Over a long period, the explosion merges with the surrounding gas, creating a shock that accelerates the particle. Thus, Supernovas generate cosmic rays. These charged particles are magnetically trapped in the supernova remnant and are expected to wash the Earth for about 100,000 years.
According to researchers, these cosmic rays can be powerful enough to destroy the ozone layer and cause long-term radiation damage to living creatures in the Earth’s biosphere.
This is a hypothesis for now.
We currently have no evidence to confirm that a distant supernova was the cause of the Late Devonian extinction. But we may have found something as good as proof
In recent years, scientists have investigated the possibility that supernovae near Earth were the basis of mass extinctions, and are tracking ancient radioactive isotopes on Earth that have only accumulated from exploding stars. The Iron-60 isotope has been the focus of many studies and has been found in numerous parts of the world.
In the context of the Late Devonian extinction, the idea that other isotopes could be a severe indicator of supernova-induced extinction was suggested by Fields and his team: plutonium-244 and samarium-146.
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“None of these isotopes spontaneously form on Earth and the only way they can get here is cosmic explosions,” says co-author ZhenghaiLiu.
In other words, if plutonium-244 and samarium-146 can be found buried in the Devonian-Carbon boundary, the researchers say it will be our rifle: interstellar evidence that implies a dying star as the trigger behind Earth’s worst extinction.
And we will never look at the sky the same way again.