A solar storm of rare intensity is heading towards Earth, and could cause problems from tonight Friday to power grids and satellites, as well as create a spectacular northern lights, the American authorities pointed out.

“We are almost certain that charged solar particles that came out of the Sun’s corona headed for Earth” Sean Dahl of the Space Weather Prediction Center (SWPC) explained at a press conference.

The Center has issued a geomagnetic storm warning Grade 4 (on a five-point scale), which has not been done since 2005.

It is difficult to predict the exact onset of the phenomenon, however will last all weekend.

“It can affect infrastructure,” Dahl said, clarifying that this phenomenon is “very rare.” “We’ve notified all the providers we work with, those that operate satellites, communications and, of course, the North American power grid,” he added.

The Sun is currently near the peak of its activity based on its 11-year cycle. These coronal mass ejections, of which at least seven are directed toward Earth, originate from a sunspot about 16 times the diameter of Earth. They move at a speed of several hundreds of kilometers per second. When they reach the American satellites it will be possible to predict more precisely the intensity of the phenomenon, that is about 20-45 minutes before reaching Earth, Sean Dahl explained.

Dahl advised the Americans to stock up with batteries or even with generators, as they do for all storms.

Electricity providers have been working to better protect their grids for a decade, said Rob Steenberg, a scientist working at SWPC. Power lines can be affected, not homes, and today there are systems in place to avoid them. The GPS network could also be affected.

Regarding air traffic, the Civil Aviation Administration (FAA) he does not expect serious problems.

The SWPC noted that some aurora may appear in the sky, even in areas where this phenomenon is not common, and advised residents to … take pictures. “If you’re in an area where it’s dark, cloudless and with minimal light pollution, you’ll be able to see very impressive auras”, Steenberg said. “And that’s the gift of space meteorology.”