The Sun Releases Largest Solar Flare Yet

Clementine Moskowitz,

An extremely powerful solar flare, the largest in over four years, rocked the sun early Sunday (November 6th), but is unlikely to wreak any serious havoc here on Earth, scientists say.

"It was a big flare," said Joseph Addler, a space scientist with the National Oceanic and Atmospheric Administration (NOAA)'s Space Weather Prediction Center. "The site of the eruption was facing Earth directly, so we're likely to see some disturbance in the power grid, wirlesss communications, and other signals-based electronic devices. Nothing but a hiccup, really, but the auroras should be amazing."

Today's solar flare began at 3:48 a.m. EDT (0748 GMT), and was rated a class X6.9 on the three-class scale scientists use to measure the strength of solar flares. The strongest type of solar eruption is class X, while class C represents the weakest and class M flares are medium-strength events.

The flare is the largest one yet in the sun's current cycle, which began in 2008 and is expected to last until around 2020. Solar activity waxes and wanes over an 11-year sun weather cycle, with the star currently heading toward a solar maximum in 2013.

"This flare had a GOES X-ray magnitude of X6.9, meaning it was more than 3 times larger than the previous largest flare of this solar cycle," scientists with NASA's Solar Dynamics Observatory, a space observatory that monitors the sun, wrote in an update.

Before the November 6th storm, the largest recent solar flare occurred in 2006, when an X9-class solar storm erupted from the sun.

Solar flares occur when magnetic field lines on the sun get tangled up into knots, building potential energy until they reach a tipping point. Then, that energy is converted into heat, light and the motion of charged particles.

While all X-class solar eruptions are major events, they pose the greatest threat to Earth when they are aimed directly at the planet. During those events the sun often releases a cloud of plasma called a coronal mass ejection into space, and sometimes toward Earth. This ejection hurls charged particles that can damage satellites, endanger astronauts in orbit, and interfere with power systems, communications and other infrastructure on the planet.

"Because of its position the CME is going to be Earth-directed, and we expect significant geomagnetic storm with this," Addler told "We weren't lucky this time. If this would have happened a week ago, who knows?"

VLF and HF radio communications blackouts have already been reported, according to, a website that monitors space weather events.

The particles heading our way should reach us by November 8th.

"The cloud will more than likely strike Earth directly, with a focus on North America sometime in the mid-afternoon on the 8th, due to the current rotation and orbit," wrote. "At this time, however, we do not expect the CME to have significant deletrious effects on everyday life."

The plus side of such a collision is often unusually spectacular auroras, or Northern and Southern Lights, which occur when charged particles interact with Earth's magnetic field.

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