A solar storm of rare intensity is heading towards Earth and could cause disruptions to electrical networks and satellites as early as Friday evening, but also impressive northern lights, American authorities have warned.
“We are almost certain that a series of coronal mass ejections, which are explosions of energetic particles and magnetic fields from the sun, are directed towards Earth,” explained Shawn Dahl at a press conference, from the US Space Weather Prediction Center (SWPC).
A warning notice concerning a geomagnetic storm of level 4, on a scale of 5, was issued — which had not been done since 2005.
Predicting the exact start time of the event is difficult, but it should persist throughout the weekend.
“There could be impacts on infrastructure,” said Shawn Dahl, specifying that it was a “very rare” event. “We have notified all the operators that we work with, such as satellite, communications and of course the power grid operators in North America,” he added.
The Sun is currently close to its peak activity, according to a cycle that returns every 11 years.
These coronal mass ejections, at least seven of which are currently heading toward Earth, come from a sunspot about 16 times the diameter of Earth.
They move at several hundred kilometers per second.
When they reach American satellites placed about 1.5 million kilometers from Earth, the intensity of the event can then be better predicted — between 20 and 45 minutes before it arrives, said Shawn Dahl.
Northern Lights
He recommended residents equip themselves with batteries or potentially generators, as with any other storm warning.
But electricity operators have worked for ten years to better protect their networks, reassured Rob Steenburgh, scientist at SWPC. The effects can only occur on high voltage lines, not in private homes, and systems comparable to circuit breakers exist, for example.
GPS signals could also be affected, he said.
Regarding air traffic, the American Civil Aviation Agency (FAA) said “do not expect significant consequences”.
The event should, however, generate northern lights, including in regions where they are not usual. SWPC officials did not want to comment on the extent of the area potentially affected but recommended that residents go out and take photos.
“If you’re somewhere where it’s dark, cloudless and with little light pollution, you might see some pretty impressive aurora borealis,” Steenburgh said. “And that really is the gift of space weather.”
