Electric ValentineAlthough they've been together for about 4.5 billion years, the sun and Earth still seem to have a downright electric relationship, based on a colorful show of northern lights seen on Valentine's Day. Above, a short but stunning aurora lights up the sky over Bø in Vesterålen, Norway.Such displays occur when the sun sends a burst of charged particles coursing toward Earth. A recent uptick in these so-called coronal mass ejections, or CMEs, that started Sunday has increased aurora activity throughout the week.(See "Biggest Solar Flare in Four Years.")—Andrew Howley
Photograph by Øystein Lunde Ingvaldsen

New Aurora Pictures: Solar Storms Light Up Arctic Night

Shimmering curtains of neon color added sparkle to Valentine's Day, as bursts of particles from the sun triggered brilliant auroras.

February 19, 2011