Video The US National Weather Service has issued a warning that a G4 solar storm will lash Earth from Friday until Sunday.
The agency’s Space Weather Prediction Center (SWPC) has been observing solar flares and coronal mass ejections (CMEs) from a sunspot 16 times wider than our home world. Five of these CME-derived solar flares are potentially directed at Earth, making for a geomagnetic storm later today.
“Additional solar eruptions could cause geomagnetic storm conditions to persist through the weekend,” the interplanetary agency noted, releasing video of one such eruption that you can see below.
CMEs are masses of charged particles – billions of tons of the stuff – and can hit speeds between 250 and 3,000 kilometres per second (150 to 1,860 miles per second). The fastest CMEs can reach Earth from our Sun in less than a day, sometimes as little as 15 hours. Given that the CMEs started on Wednesday, and the first will reach our planet today, and some of them might be on the slower end of the spectrum.
CMEs can have potential consequences for electronic infrastructure and devices; NASA cautioned that a solar flare in February could have knocked out some communications in space and on Earth. If a solar storm is particularly powerful, astronauts on the International Space Station will be advised to shelter in a specially shielded section of the orbiting lab.
The SWPC similarly warns that the impending CMEs may interfere with “communications, the electric power grid, navigation, radio and satellite operations.” The teams that maintain these critical systems have been given at least 48 hours of notice, thanks to America’s network of sun-watching satellites, so they can take necessary precautions.
If the CME solar storm from December is any indication, we might just look forward to auroras (also called the Northern Lights or aurora borealis) that stretch far more to the south than they usually do. The SWPC says the light show could cover most of the continental US, except for most of the Southwest and Florida.
The December CMEs were in the G3 class, whereas the upcoming CMEs are rated as G4. Solar storms on the higher end of the spectrum can certainly be dangerous, such as the G5-class Halloween Storms in 2003, which caused blackouts in Sweden and damaged transformers in South Africa.
Given that G4 isn’t quite as bad as G5 but is still a step up from G3, it’s not entirely clear if we’ll be treated to rare auroras across the northern hemisphere or if there will be actual damage to power grids. ®