Batten down the hatches, people. A giant solar flare that arced off the sun on Wednesday afternoon is heading for Earth, and scientists say it could disrupt our planet's power and communication grids when it crosses our path on Friday and Saturday. It's the largest solar storm in years.
NASA has issued a geomagnetic storm watch, cautioning that the flare could affect unprepared electrical systems. Though the flare was classified as an ominous-sounding "X-class" event (an X1.6, in the high-intensity category), you can relax: NOAA space weather forecaster Bill Murtagh told the media that though the event is expected to cause "geomagnetic storm levels in the G2 (moderate) and G3 (strong) range," problems with power grids on that scale are "typically very manageable." Satellite operators may have to deal with increased interference.
Still, CNN meteorologist Chad Myers said, "This is a pretty strong solar storm, and we just won't know until it gets here." NASA released an ominous video of the solar flare, which is both gorgeous and not exactly reassuring.
Solar flares, the European Space Agency explains, are formed when "energy stored in 'twisted' magnetic fields (usually above sunspots) is suddenly released." The resulting flare is supercharged with radiation of every sort; Tech Times' Rhodi Lee writes that the most intense flares can carry up to six times the energy being emitted by the sun at any given second. The current storm also triggered a coronal mass ejection (CME), which the ESA describes as "huge bubbles of gas threaded with magnetic field lines that are ejected from the Sun over the course of several hours."
"There's been a giant magnetic explosion on the sun," Tom Berger, director of the Space Weather Prediction Center, explained to the Associated Press. "Because it's pointed right at us, we'll at least catch some of the cloud." But he added, "We're not scared of this one."
The largest flares may have the potential to knock out unhardened satellites and bring down infrastructure all around the planet; NASA scientists have concluded that another occurrence of the largest flare in recorded history, the 1859 Carrington Event, could cause $2 trillion in damage and take years to repair critical equipment. The chance of such a scenario occurring between 2012 and 2022 was around 12%, and the planet barely dodged a flare that could have reached similar proportions in 2012.
"Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground," NASA said in a statement. "However — when intense enough — they can disturb the atmosphere in the layer where GPS and communications signals travel."