Raging sun provides earthly light show

At the tumultuous peak of its 11-year activity cycle, the sun is spitting out X-ray flares and belching giant clouds of high-energy particles at a furious rate.

Northern lights photographed on April 11 in New Mexico. Grohusko

On April 2, the sun unleashed the most powerful flare recorded since regular

measurements began 25 years ago.

Packing more energy than 100 megatons of TNT, the flare erupted from a turbulent

region on the sun’s northwest edge that had grown to be 13 times bigger than

Earth’s surface. Because the explosive region soon rotated onto the sun’s far

side, Earth was spared the brunt of the storm. Nonetheless, ultraviolet and X-ray

radiation from the flare triggered a temporary radio blackout on Earth’s sunlit


The flare was more powerful than the infamous one that disrupted power grids in

Canada on March 6, 1989, during the peak of the last solar cycle, notes Paal

Brekke, a European Space Agency scientist based at NASA’s Goddard Space Flight

Center in Greenbelt, Md.

With solar activity expected to continue at a peak level for another year, the

sun’s rage is far from over. Over the past few weeks, coronal mass ejections–huge

clouds of electrified gas hurled from the sun’s outer atmosphere–have created

giant shock waves that plowed into Earth’s magnetosphere, our planet’s magnetic

cocoon. These waves generated powerful geomagnetic storms. As a result, charged

particles that normally crash into Earth’s polar regions creating the shimmering

lights known as auroras moved to lower latitudes.

Sky watchers observed dazzling displays of these so-called northern lights as far

south as Mexico. “It was a wide or broad veil of a silvery yet delicately faint

glow in the northern sky,” says Chris Grohusko of El Paso, Texas, describing the

aurora borealis he photographed in southern New Mexico on April 11.

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