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On thing keeps me awake at night, and during the day, for that matter: GRBs. Gamma Ray Bursts. If one occurred relatively close to the earth, and was aimed right at us, well, things would not go well. And now, Looks like they may be stronger than thought..
An international team of astronomers has detected a pair of gamma-ray bursts with energies more powerful than anything ever seen before. GRBs are the strongest explosions known in the cosmos, but these latest observations suggests we’ve significantly underestimated their true potential.
Three new papers published today in Nature describe two new gamma-ray bursts—GRB 190114C and GRB 180720B—both of which yielded the highest-energy photons ever recorded for GRB events. The unprecedented observations are casting new light—quite literally—onto these mysterious cosmic events and the mechanics behind them.
Gamma-ray bursts are thought to be triggered when gigantic stars collapse into black holes, causing a supernova. The resulting explosion produces a powerful, concentrated jet that shoots material into space at 99.99 percent the speed of light. The rapidly accelerating particles within the jet produce gamma rays through complex interactions with magnetic fields and radiation. The ensuing gamma rays continue to travel through interstellar space, some of which eventually reach Earth. When they come into contact with our atmosphere, gamma rays trigger a particle cascade that in turn generates a phenomenon known as Cherenkov light, which can be detected by specially equipped telescopes.
Details:
The first of these high-energy events, GRB 180720B, happened on July 20, 2018, and is described in a paper led by astronomers from the Max Planck Institute, Deutsches Elektronen-Synchotron (DESY), the International Centre for Radio Astronomy Research (ICRAR), and several other institutions. The second event, GRB 190114C, occurred on January 14, 2019, and is described in two new papers (here and here), both led by Razmik Mirzoyan from the Max Planck Institute for Physics. Over 300 scientists from around the world were involved in the research.
(Score: 1) by khallow on Thursday November 21 2019, @10:24PM (3 children)
(Score: 0) by Anonymous Coward on Friday November 22 2019, @03:08PM (2 children)
Not at all. The main reason we're alive today is that gamma ray bursts tend to be relatively thin. We're now able to detect, on average, about one a day. It's like we're at a party and some asshole in the center just keeps shooting bullets in random directions. Relative is, of course, relative. For instance a beam could be as wide as the Earth - but they are nowhere near large enough to encompass anything like the entire solar system or we'd long since have been toast a million times over. Well that or evolved to not rely on our current form of atmosphere.
And also by the time they get to us they've mostly blown their load. So when you read things like these things having as much energy concentrated into a few seconds as the sun will in its 10 billion year lifetime, you have to keep in mind electromagnetic goodies, including GRBs, all are subject to inverse square laws. Double a distance, reduce the inensity by 1/4th, triple it 1/9th, quadruple it 1/16th, etc. And the GRBs tend to originate from really really far away. These events were 4-6 billion light years away. So you're not experiencing this crazy power at exposure, it takes that crazy power to create a signal strong enough that any of it gets to us!
(Score: 1) by khallow on Friday November 22 2019, @04:24PM (1 child)
Or light years across. The point is that it takes a lot less energy for a GBR to kill things in space than to kill things on Earth.
(Score: 1) by khallow on Friday November 22 2019, @04:29PM