Cosmic blast seared Earth ’s atmosphere from 2 billion light-years away

On 9 October 2022, for 7 minutes, high energy photons from a gigantic explosion 1.9 billion light-years away toasted one side of Earth as never before observed. The event, called a gamma ray burst (GRB), was 70 times brighter than the previous record holder. But what astronomers dub the “BOAT”—the brightest of all time—did more than provide a light show spanning the electromagnetic spectrum. It also ionized atoms across the ionosphere, which spans from 50 to 1000 kilometers in altitude, researchers say. The findings highlight the faint but real risk of a closer burst destroying Earth’s protective ozone layer. “It was such a massive event, it affected all levels of the atmosphere,” says solar physicist Laura Hayes of the European Space Agency (ESA). Astronomers aren’t yet sure what causes a GRB, which we see shining as intensely as a bright star in the Milky Way, despite being billions of times more distant. To hurl so much energy across billions of light-years, GRBs must be among the biggest explosions since the big bang. At least some of them may be born in a particular type of supernova that occurs when a dying, massive star collapses into a neutron star or black hole. A typical GRB releases as much energy in a few seconds as the Sun will in its entire 10-billion-year lifetime. Even by those standards, the October 2022 event, known as GRB 221009A, was exceptional, saturating detectors on NASA’s Fermi Gamma-ray Space Telescope and leaving ...
Source: Science of Aging Knowledge Environment - Category: Geriatrics Source Type: research