Photo of the Day 2 April 2008

Aurora Borealis, Acadia National Park, Maine, 2005
Photograph by Michael Medford
Nature's light show—aurora borealis—bathes Maine's Acadia National Park in a pink glow. These dazzling patterns in nature, called aurora australis in the Southern Hemisphere, are created when charged particles outside the Earth's atmosphere collide with atoms in the upper atmosphere, producing a glowing display of curtains, arcs, and bands stretching across the sky.