CAPE CANAVERAL, Fla. (AP) — An unusually strong solar storm could produce aurora borealis in the United States this weekend, disrupting power and communications.
The National Oceanic and Atmospheric Administration issued a rare severe geomagnetic storm warning Friday afternoon after a solar explosion reached Earth several hours earlier than expected. The effects were expected to last through the weekend and possibly into next week.
NOAA warned operators of orbiting power plants and spacecraft, as well as the Federal Emergency Management Agency, to take precautions.
“For most people on Earth, there's no need to do anything,” says Rob Steenberg, a scientist at NOAA's Space Weather Prediction Center.
AP correspondent Shelley Adler reports solar storm could impact U.S.
The storm could produce aurora borealis as far south as Alabama and Northern California, according to the National Oceanic and Atmospheric Administration (NOAA). But it's difficult to predict, and experts stressed it was more like a splash of greenish hues rather than the dramatic curtains of color usually associated with the aurora borealis.
“It's really a gift from space weather: the aurora borealis,” Steenberg said. He and his colleagues said the best views of the aurora borealis may come from cell phone cameras, which are better at capturing light than the naked eye.
When you take a photo of the sky, “there might actually be a nice little reward in there,” said Mike Betwee, the prediction center's director of operations.
In 1859, the most intense solar storm in recorded history occurred, possibly producing aurora borealis in Central America and even Hawaii. NOAA space weather forecaster Sean Dahl said “we're not expecting that,” but it could be close.
Dahl told reporters that the storm (rated No. 4 on a scale of 1 to 5) poses a risk to the power grid's high-voltage power lines, not the power lines in homes. Satellites may also be affected, potentially disrupting navigation and communication services on Earth.
For example, an extreme geomagnetic storm in 2003 caused power outages in Sweden and damaged transformers in South Africa.
Since Wednesday, the sun has unleashed a strong solar flare that has triggered at least seven bursts of plasma. Each eruption, known as a coronal mass ejection, can contain billions of tons of plasma and magnetic fields from the Sun's outer atmosphere, or corona.
The flare appears to be associated with a sunspot 16 times the diameter of Earth, NOAA said. This is all part of solar activity, which is increasing as the sun approaches the peak of its 11-year cycle.
NASA said the storm posed no significant threat to the seven astronauts aboard the International Space Station. Steenberg said the biggest concern is rising radiation levels, and the crew could be moved to a more shielded part of the station if necessary.
Increased radiation levels could also threaten some of NASA's scientific satellites. Antti Pulkinen, head of the space agency's heliophysics science division, said highly sensitive equipment would be powered down if necessary to avoid damage.
Several sun-focused spacecraft monitor all activity.
“This is exactly the kind of thing we want to observe,” Pulkinen said.
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