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Second solar storm hits earth ( 2003-10-31 11:43) (Agencies)
A second huge magnetic solar storm hit Earth on Thursday, just a day after an earlier one hurtled into the planet in what one astronomer called an unprecedented one-two punch.
Kohl, the lead investigator for an instrument aboard NASA's sun-watching SOHO spacecraft, said the probability of two huge flares aimed directly at Earth coming so close together, as they have this week, was "unprecedented ... so low that it is a statistical anomaly."
While such solar storms do not directly endanger humans, the charged particles can play havoc with electric grids, satellites and other equipment. They can also create spectacular displays of the northern and southern lights.
To brace for any possible energy surges, power plants from Sweden to New Jersey cut production to limit how much electricity was flowing over transmission grids. A Japanese communications satellite temporarily stopped operations earlier in the week.
Kohl said the second solar storm, known as a coronal mass ejection, peeled off the sun around 4 p.m. EST Wednesday. Charged particles from the ejection started arriving at Earth around 10 a.m. EST Thursday.
This was just a day after an earlier ejection was first detected on Earth, arriving around 1 a.m. EST Wednesday.
MOVING FASTER
The second blast from the sun was moving even faster than the first one did, and some particles from the first linger even as the second onslaught continues, Kohl said in a telephone interview.
Kohl said the first storm traveled at a top speed of 4.9 million miles per hour, while the one that hit on Thursday moved at 5.2 million miles an hour.
The X-ray and solar radiation storms rank as the second largest such events recorded in the latest 11-year cycle, according to NOAA data. Records of solar cycles date from 1755. This is the tail end of the 23rd cycle.
Wednesday's geomagnetic particle storm measured G5, or extreme, making it one of the three or four strongest such storms in the latest 11-year cycle. By contrast, Kohl said the storm that hit on Thursday was a K8, still substantial but not as intense as the previous one.
An astronomer at the University of Iowa even managed to detect the sounds made by the first storm: a clicking noise that resembled an old-fashioned telegraph, followed by a whoosh that sounded like a jet engine.
Don Gurnett, a space physicist at the university, said in a statement these sounds of the solar flare were picked up on Tuesday by NASA's Cassini spacecraft as it headed for a rendezvous with Saturn and its moons.
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