2024-05-05 05:10:54
Theories have varied, including the suggestion that human-level intelligence is completely “unique” in the Universe, but one scientist has revealed another plausible scenario – alien civilizations could have been wiped out by gamma-ray bursts (GRBs).
GRBs are extremely energetic explosions that have been recorded in distant galaxies and occur when the core of a massive star runs out of nuclear fuel and collapses under its own weight, releasing massive “supernova” radiation.
“It’s a highly focused beam, and if it was directed across the galactic plane, it could basically ‘sterilize’ about 10 percent of the space.” galactic planets,” says Frederick Walter, Ph.D., professor of astronomy.
NASA calls gamma-ray bursts “the most powerful class of explosions in the Universe.”
A typical explosion emits a bright beam of concentrated energy one quintillion times the luminosity of our Sun. In other words, it is quite enough to wipe out an extraterrestrial civilization.
Fortunately, according to decades of research by NASA’s orbiting Compton Gamma-ray Observatory, gamma-ray bursts are relatively rare in our home galaxy, the Milky Way.
When in 1991 Compton Observatory satellite was launched, NASA researchers expected to see more GRBs emanating from our galactic disk. However, it turns out that these phenomena are much more common in younger, more distant galaxies, where new stars are still forming intensively or collapsing stars are turning into black holes.
“It is estimated that approximately every 100 million every year a gamma-ray burst occurs in any galaxy,” says Dr. F. Walter, who taught a course on the search for extraterrestrial life at Stony Brook University in New York (USA).
Other estimates put gamma-ray bursts in the galaxy no more than once every 10 million years, but any interval would mean that many alien species could be wiped out before they could conduct extensive space exploration.
F. Walter points out that the Earth is approximately 4.5 billion years old. years—and it took nearly as long to evolve the only technologically advanced species that humanity currently has evidence of: humanity itself.
This would mean that between 45 and 450 GRBs could have occurred in the Milky Way during Earth’s history.
Some geophysicists and other researchers suggest that around 359-445 million years ago, Earth’s Ordovician and/or Devonian mass extinction may have been the result of a gamma-ray burst caused by just such a collapsing star or black hole.
However, F. Walter emphasizes that this is only one of the hypotheses why humanity has not yet discovered traces of an extraterrestrial civilization somewhere in the Universe.
Although these bursts can be apocalyptic, Walter reassures us that any potential GRB threat to humanity is “nothing to worry about.”
“They are rare and concentrated, so they are much less likely to hit Earth.” Besides, it’s not something you can prepare for,” says the astronomer.
Parenting page “Newsweek”.
2024-05-05 05:10:54