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Astronomers Solve Puzzle of Mysterious Streaks In Radio Images of the Sky 66

KentuckyFC (1144503) writes 'Back in 2012, astronomers constructed an array of 256 radio antennas in the high deserts of New Mexico designed to listen for radio waves produced by gamma ray bursts, one of the most energetic phenomena in universe and thought to be associated with the collapse of a rapidly rotating stars to form neutron stars and black holes. The array generates all sky images of signals produced in the 25 MHz to 75 MHz region of the spectrum. But when researchers switched it on, they began to observe puzzling streaks across the sky that couldn't possibly be generated by gamma ray bursts. One source left a trail covering more than 90 degrees of the sky in less than 10 seconds. This trail then slowly receded to an endpoint which glowed for around 90 seconds. Now the first study of these transient radio signals has discovered that they are almost certainly produced by fireballs as they burn up after entering the Earth's atmosphere. The conclusion comes after the researchers were able to match several of the radio images with visible light images of fireballs gathered by NASA's All Sky Fireball Network. That solves the mystery but not without introducing another to keep astrophysicists busy in future. The question they're scratching their heads over now is how the plasma trails left by meteors can emit radio waves at this frequency.'
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Astronomers Solve Puzzle of Mysterious Streaks In Radio Images of the Sky

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  • by the_other_chewey ( 1119125 ) on Saturday June 07, 2014 @02:48AM (#47185363)

    From the paper: "If a magnetic eld of 10 to 15 G were present within the trail, it follows that cyclotron radiation would be emitted at the observed frequencies by the electrons in the plasma. However, the surface geomagnetic eld is only 0.5 G, so this would require the generation of a strong magnetic eld by a reball, an eect that has never been observed."

    Hey, you! Your ligatures aren't showing!

Q: How many IBM CPU's does it take to execute a job? A: Four; three to hold it down, and one to rip its head off.