Solar storm effects expected this morning

The space weather forecast for Earth's neighborhood is stormy through this morning at least, as the sun belched another huge cloud of highly charged particles toward Earth on Wednesday afternoon.

A previous, unusually powerful magnetic storm struck Earth early Wednesday, but it apparently didn't trigger big power blackouts or other major problems.

The new ejection, whipping toward Earth at perhaps 4 million to 5 million miles an hour, was expected to arrive Thursday with effects lingering into today or longer. It appeared comparable in strength to the prior one.

The solar outbursts, which also include radiation from protons moving at near the speed of light, pose no direct danger to people on Earth's surface. Such solar activity can damage satellites and disrupt high-frequency radio communications and electric power networks.

Japanese space agency officials said they'd lost contact with an environmental observation satellite on Saturday, perhaps because of earlier solar activity. The agency has also shut down a communications satellite because of storm damage.

The Federal Aviation Administration on Wednesday recommended that planes fly below 25,000 feet at latitudes above 35 degrees north and south because of possible high radiation doses. But on Thursday the agency removed its alert, saying radiation levels weren't excessive. In the United States, 35 degrees north stretches approximately from Charlotte, N.C., to Santa Barbara, Calif.

The solar activity can create spectacular auroras as the charged particles slam into Earth's outer magnetic field. Combs said such light shows had been observed as far south as Texas, Arizona and Alabama. They might appear Thursday night as well, he said.

"They're beautiful, too, green and red ... and shimmering and quite a display," said John Kohl, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics.

Kohl said he's not aware of any other time since at least 1976 that two such large solar storms have been directed toward Earth in the space of two days.

Such storms have caused power disturbances in the United States and Canada at least 11 times since 1940 because they generate currents that flow through Earth's surface, which in turn can disrupt utility operations. But utilities can take precautions and have been keeping an eye on the latest storm situation. No U.S. blackouts had been reported as of midday Thursday.

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On the Net:

NOAA Space Environment Center Space Weather Outlook:

http://www.sec.noaa.gov/SWN/

Harvard-Smithsonian Center:

http://cfa-www.harvard.edu/press/pr0323.html