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Explosions In Space May Have Initiated Ancient Extinction On Earth Scientists at NASA and the University of Kansas say that a mass extinction on Earth hundreds of millions of years ago could have been triggered by a star explosion called a gamma-ray burst. The scientists do not have direct evidence that such a burst activated the ancient extinction. The strength of their work is their atmospheric modeling -- essentially a "what if" scenario. The scientists calculated that gamma-ray radiation from a relatively nearby star explosion, hitting the Earth for only ten seconds, could deplete up to half of the atmosphere's...

A DEVASTATING burst of gamma-rays may have caused one of Earth's worst mass extinctions, 443 million years ago. A team of astrophysicists and palaeontologists says the pattern of trilobite extinctions at that time resembles the expected effects of a nearby gamma-ray burst (GRB). Although other experts have greeted the idea with some scepticism, most agree that it deserves further investigation. GRBs are the most powerful explosions known. As giant stars collapse into black holes at the end of their lives, they fire incredibly intense pulses of gamma rays from their poles that can be detected even from across the universe...

A brilliant burst of gamma rays may have caused a mass extinction event on Earth 440 million years ago—and a similar celestial catastrophe could happen again, according to a new study. Most gamma-ray bursts are thought to be streams of high-energy radiation produced when the core of a very massive star collapses. Such a disaster may have been responsible for the mass die-off of 70 percent of the marine creatures that thrived during the Ordovician period (488 to 443 million years ago), suggests study leader Brian Thomas, an astrophysicist at Washburn University in Kansas. The simulation also shows that a...

A beautiful pinwheel in space might one day blast Earth with death rays, scientists now report. Unlike the moon-sized Death Star from Star Wars, which has to get close to a planet to blast it, this blazing spiral has the potential to burn worlds from thousands of light-years away. "I used to appreciate this spiral just for its beautiful form, but now I can't help a twinge of feeling that it is uncannily like looking down a rifle barrel," said researcher Peter Tuthill, an astronomer at the University of Sydney. The fiery pinwheel in space in question has at its...

Explanation: Might this giant pinwheel one-day destroy us? Probably not, but investigation of the unusual star system Wolf-Rayet 104 has turned up an unexpected threat. The unusual pinwheel pattern has been found to be created by energetic winds of gas and dust that are expelled and intertwine as two massive stars orbit each other. One system component is a Wolf-Rayet star, a tumultuous orb in the last stage of evolution before it explodes in a supernova -- an event possible anytime in the next million years. Research into the spiral pattern of the emitted dust, however, indicates the we are...

Earth may lie in the path of a dangerous gamma-ray burst that could wipe out a quarter of our atmospheric ozone. Astronomers say that WR 104, a Wolf-Rayet star about 8,000 miles away, could go supernova any day, which would generate gamma-rays that could reach Earth.