New Year's Aurora
Part of the new year's first big display of northern lights, an aurora borealis appears to dip into the mountains near Tromsø in northern Norway on January 7.
The auroras, which continued into the second week of the year, were rooted in strong "gusts" of solar wind—actually charged particles—set in motion by sun activity in the first week.
Auroras are created when such charged particles flow along Earth's magnetic field lines. The particles hit the atmosphere at the Poles and excite air molecules, which release the extra energy as light.
(See more aurora pictures.)
New Aurora Pictures: First Big Show of 2011
In the year's first big northern lights show, "gusts" of solar wind set the Arctic sky alight in shades of green.