186
A supernova explosion in the constellation Scorpius Centaurus, which occurred between 2 and 3 million years ago, may have caused a burst of cosmic radiation that influenced the evolution of living organisms on Earth.
A study conducted by a team of astrophysicists led by Caitlin Nogieri showed a coincidence in time between this explosion and the increase in viral diversity in Lake Tanganyika. Scientists suggest that the radiation that emerged after the supernova could have caused mutations, affecting the development of microorganisms.
Astronomers believe that the solar system is in a so-called Local bubble – a zone cleared of stars by supernova explosions millions of years ago. Earth’s passage through such regions, enriched in the isotope iron-60, correlates with periods of increased cosmic radiation. Studies of marine sediments have confirmed two bursts of iron-60, one of which dates back 1,5–3,2 million years ago.
Computer modeling showed that The Earth was exposed to intense radiation for 100 years after the supernova explosion. For the Scorpio-Centauri event, the radiation level could reach 30 milligrays per year, and in the case of the Tucana-Gorodia explosion, up to 100 milligrays, which significantly exceeds the threshold values for DNA damage.
In parallel with the increase in background radiation A sharp increase in viral diversity has been recorded in Lake Tanganyika. This may be a coincidence, but scientists do not rule out a connection.
New research confirms that Space events can have a significant impact on the Earth's biosphere. This forces us to reconsider traditional ideas about evolutionary mechanisms, because the influence of radiation from supernovae may play an important role in biological processes on Earth. “We are all stardust,” – as Carl Sagan said, and perhaps stellar cataclysms influenced evolution more than we previously thought.
