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Joined: Sep 10, 2003 Posts: 6460 Location: UK
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Posted: Thu Oct 30, 2003 3:28 pm Post subject: Major Solar Storm |
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The most powerful solar storm in decades continued to buffet Earth Thursday morning while another major storm appeared headed for the planet by Friday. The back-to-back pairing of two historically huge flares is unprecedented, one physicist says.
There is a chance the two storms could join forces as the second one catches up with the first.
The initial blast of solar material temporarily disabled one satellite, caused radio blackouts that affected airline traffic, and forced power grid managers to take safety precautions by reducing transmissions. It would have been worse, said Joe Kunches, the SEC's lead forecaster, if not for the ability to predict the storm's timing and intensity.
When it left the Sun on Tuesday, the first cloud of charged particles was an undeniable monster. Its expanding bubble of hot gas -- a coronal mass ejection -- was photographed by the SOHO spacecraft as it left the Sun. Radiation from the flare arrived in about 8 minutes and generated radio disruptions.
The biggest danger comes when a storm's physical material -- the charged particles -- slams into Earth's otherwise protective sphere of magnetism, which can be overwhelmed.
If the storm's magnetic field is pointed in the same direction as Earth's, as this one was for most of the time, then it slips by comparatively calmly, Golub explained. But if it's oriented in the opposite way, as this one was near the beginning of the event and again late yesterday, then the two magnetic fields essentially join forces. Scientists call it reconnection.
The effect is to take existing particles near Earth -- not the ones that arrived from the Sun -- and accelerate them. It's like "pumping up the energy," another scientist said. These particles can slam into satellites and cause electrical shorts. They excite molecules in the atmosphere and create colorful lights called aurora. And they even induce electrical currents in wires on the ground.
A really strong storm can also compress Earth's magnetosphere to the extent that the highest satellites, those in geostationary orbits some 22,300 miles up, are suddenly outside the protective field "and are bombarded by solar wind particles too," says Paal Brekke, deputy project scientist for SOHO.
The Sun-watching probe is managed by NASA and the European Space Agency.
[Source:Space.com] |
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