An unusually strong solar storm that struck Earth produced stunning displays of color in the northern hemisphere sky early Saturday, with no immediate reports of power and communications disruptions.
The U.S. National Oceanic and Atmospheric Administration issued a rare severe geomagnetic storm warning when a solar burst reached Earth Friday afternoon, hours earlier than expected. The effects of the Northern Lights, which were clearly visible in Britain, were expected to last through the weekend and possibly into next week.
Many people in the UK shared phone snaps of the lights on social media early Saturday, with the phenomenon seen as far away as London and southern England.
There were sightings “up and down across the country”, said Chris Snell, a meteorologist at the Met Office, Britain’s weather agency. He added that the office had received photos and information from other European locations, including Prague and Barcelona.
NOAA alerted operators of power plants and orbiting spacecraft, as well as the Federal Emergency Management Agency, to take precautions.
“For most people here on planet Earth, they won’t have to do anything,” said Rob Steenburgh, a scientist at NOAA’s Space Weather Prediction Center.
The storm could produce northern lights as far south in the United States as Alabama and Northern California, NOAA said. But it was difficult to predict and experts stressed that it would not be the spectacular curtains of color normally associated with the Northern Lights, but rather pops of greenish hues.
“That’s truly the gift of space weather: the northern lights,” Steenburgh said. He and his colleagues said the best views of aurora might come from phone cameras, which capture light better than the naked eye.
Take a photo of the sky and “there might be a little treat there for you,” said Mike Bettwy, chief of operations for the forecast center.
The most intense solar storm in recorded history, in 1859, brought auroras to Central America and perhaps even Hawaii. “We’re not predicting that,” but it could be close, said Shawn Dahl, a NOAA space meteorologist.
This storm poses a risk to high-voltage transmission lines in power grids, not power lines typically found in homes, Dahl told reporters. Satellites could also be affected, potentially disrupting navigation and communications services on Earth.
An extreme geomagnetic storm in 2003, for example, knocked out power in Sweden and damaged power transformers in South Africa.
Even after the storm passes, signals between GPS satellites and ground receivers could be jammed or lost, according to NOAA. But there are so many navigation satellites that the outages shouldn’t last long, Steenburgh noted.
The sun has produced strong solar flares since Wednesday, resulting in at least seven plasma explosions. Each flare, known as a coronal mass ejection, can contain billions of tons of plasma and magnetic field from the Sun’s outer atmosphere, or corona.
The flares appear to be associated with a sunspot that is 16 times the diameter of Earth, NOAA said. It’s all part of solar activity that intensifies as the sun approaches the peak of its 11-year cycle.
NASA said the storm posed no serious threat to the seven astronauts aboard the International Space Station. The biggest concern is increased radiation levels, and the crew could move to a better-protected part of the station if necessary, according to Steenburgh.
Increased radiation could also threaten some NASA science satellites. The extremely sensitive instruments will be turned off, if necessary, to avoid damage, said Antti Pulkkinen, director of the space agency’s heliophysics science division.
Multiple sun-focused spacecraft monitor all the action.
“This is exactly the kind of thing we want to observe,” Pulkkinen said.
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