Solar Flare Could Trigger Auroras Tonight For Northern U.S.

Earth is in the line of fire of a powerful solar flare that has already begun hitting us, but most of the energy from the Coronal Mass Ejection, or CME, will skirt safely by, scientists say, with major disruptions to the electric grid, satellites and communications unlikely.

But if you're lucky — and far enough north — you might see a nice display of aurora borealis.

Sky & Telescope says the X-class flare "should ... produce moderate-to-strong auroras over the weekend." The magazine adds:

"On Wednesday afternoon, the Sun erupted with a powerful flare that peaked at 1:48 p.m. Eastern Daylight Time. From its perspective in space, NASA's Solar Dynamics Observatory captured the titanic explosion, which covered an area several times larger than Earth."

By 9:15 p.m. ET Thursday, the effects were being felt in the form of a potentially aurora-producing geomagnetic storm, according to the National Oceanic and Atmospheric Administration's Space Weather Prediction Center. It says the impact of the CME should be with us through Sunday.

(For more about space weather — geomagnetic storms, CMEs, sunspots, etc., NASA has an FAQ page here.)

NOAA space weather forecaster Bill Murtagh says we should expect those geomagnetic storm levels to reach the moderate (G2) to strong (G3) range.

"G2-G3 geomagnetic storms can cause some problems for the (power) grid but are typically very manageable," Murtagh wrote in an email Thursday to USA Today. "We may also see some anomalies with satellites so satellite operators around the world have been notified. And problems with the accuracy of GPS have been observed with this level of storming."

NPR's Nell Greenfieldboyce says that according to NOAA, the strongest geomagnetic storming expected to occur late Friday night and into Saturday morning" and northern lights are possible Friday night across the northern part of the U.S., from New England through the Great Lakes to Washington and Oregon.

Two years ago, the Earth narrowly escaped being hit by a CME so big that if it had been in the bull's-eye "we would still be picking up the pieces," according to Daniel Baker, director of the University of Colorado's Laboratory for Atmospheric and Space Physics.

The 2012 event that missed us would have been the most powerful CME in 150 years to hit Earth.

The last time for such a massive flare was in 1859 — the so-called Carrington Event.

Named after English astronomer Richard Carrington, who first observed the massive flare, it produced a global knockout blow to the most sophisticated electrical infrastructure of its day. History.com says:

"[Telegraph] communications around the world began to fail; there were reports of sparks showering from telegraph machines, shocking operators and setting papers ablaze. All over the planet, colorful auroras illuminated the nighttime skies, glowing so brightly that birds began to chirp and laborers started their daily chores, believing the sun had begun rising. Some thought the end of the world was at hand, but Carrington's naked eyes had spotted the true cause for the bizarre happenings: a massive solar flare with the energy of 10 billion atomic bombs. The flare spewed electrified gas and subatomic particles toward Earth, and the resulting geomagnetic storm—dubbed the "Carrington Event"—was the largest on record to have struck the planet."

There have been more recent large X-class flares, but the largest of them, like the one in 2012, were (thankfully) not aimed at us.