It was never seen as a threat to people, just technology, and teased skywatchers with the prospect of colorful Northern Lights dipping further south.
But when the storm finally arrived, after traveling at 2.7 million mph (4.3 million kph), it was more a magnetic breeze than a gale. The power stayed on. So did satellites. And the promise of auroras seemed to be more of a mirage.
Scientists initially figured the storm would be the worst since 2006, but now seems only as bad as ones a few months ago, said Joe Kunches, a scientist at the NOAA center. The strongest storm in recorded history was probably in 1859, he said.
“It’s not a terribly strong event. It’s a very interesting event,” Kunches said.
Forecasters can predict the speed a solar storm travels and its strength, but the north-south orientation is the wild card. This time it was a northern orientation, which is “pretty benign,” Kunches said. Southern would have caused the most damaging technological disruption and biggest auroras.
North American utilities did not report any problems, said Kimberly Mielcarek, spokeswoman for the North American Electric Reliability Corporation, a consortium of electricity grid operators. Her office did not respond to a phone call.
Astronomers say the sun has been relatively quiet for some time. And this storm, forecast to be strong and ending up minor, still may seem fiercer because Earth has been lulled by several years of weak solar activity.
The storm is part of the sun’s normal 11-year cycle, which is supposed to reach a peak next year. Storms as large as the latest one will probably happen several more times as the cycle ramps up to that peak, scientists said.
The region of the sun that erupted can still send more blasts our way, Kunches said. Another set of active sunspots is ready to aim at Earth.
“This is a big sun spot group, particularly nasty,” NASA’s Hathaway said. “Things are really twisted up and mixed up. It keeps flaring.”
Storms like this start with sun spots. First, there’s an initial solar flare of subatomic particles that resembles a filament coming out of the sun. That part usually reaches Earth only minutes after the initial burst, bringing radio and radiation disturbances. Next is the coronal mass ejection, which looks like a growing bubble and takes a couple days to reach Earth.
Solar storms have three ways they can disrupt technology on Earth: with magnetic, radio and radiation emissions.<< previous 1 2