Northern lights are created when charged particles are flung off the surface of the sun, travel to Earth, and get funneled down to the poles along magnetic field lines. The particles collide with molecules in our atmosphere, transferring energy and making the air molecules glow like a neon sign. (Learn more about auroras.)
Curtains of Light
Dancing multicolored auroras spread over the forests of interior Alaska in a picture taken March 17 and submitted to National Geographic's Your Shot community.
"We stayed out viewing and photographing the aurora until after 3 a.m.," said sky photographer Susan Stevenson. "It was an amazing and soulful experience!"
Neon Green Aurora
Two days after the onset of the St. Patrick's Day geomagnetic storm, the skies above the Reykjanes peninsula in Iceland (map) were still charged with enough energy to produce auroras bright enough to compete with the glare of the moon.
The colors a sky-watcher sees depends on the type of gas being hit and how high it occurs. For example, the green aurora pictured was the result of collisions between oxygen atoms and solar particles about 60 to 120 miles (100 to 200 kilometers) up.
In a picture taken February 14, northern lights appear to touch down between two Scandinavian mountain peaks.
The frequency and intensity of auroras this past year have been on the rise as the sun approaches what's known as solar maximum in the next few months.
Looking like a cosmic whirlpool enveloping the entire sky, a particularly intense peak in the northern lights near Yellowknife (map), in Canada's Northwest Territories, was captured by a fish-eye lens on March 1.
During the Northern Hemisphere's springtime, solar magnetic fields are oriented in just the right way to cause "rips" in Earth's magnetic field, allowing more of the sun's charged particles to reach our atmosphere.
The resulting increase in solar winds on Earth encourages auroral sky shows, but can also damage satellite technology and electrical grids on the ground.
Bands of glowing auroras stride across the snow-covered plains of Canada's Northwest Territories in a picture taken February 21.
"Just for a couple of minutes the clouds had left a bit and finally I had the luck to see the bright northern light," said astrophotographer Nicole Schafer.
"It was worth every second to wait and see the magical lights ... Nature shows you everything she [has], if you are patient enough."
Auroras bloom in a spectacular magenta- and green-colored starburst captured March 9 above the snow-capped mountains of the Brooks Range in Alaska—about 200 miles (321 kilometers) north of the Arctic Circle.
"The aurora filled most of the sky, and exceeded the reach of my [super-wide-angle] 15mm camera lens," said photographer Wayne Barsky.
An unusually strong burst of green auroras paints the skies over Fairbanks, Alaska, on March 17.
While that weekend's geomagnetic storms were essentially atmospheric fireworks, solar storms have the potential to be a danger to spacewalking astronauts, Earth-orbiting satellites, and even communications and electrical systems on the ground.
When a coronal mass ejection, or solar wind, enters Earth's upper atmosphere, its charged particles smash into and break up gas molecules, which give off energy in the form of the so-called northern lights (or in the Southern Hemisphere, southern lights).
Celestial Fish Hook
Like a giant, cosmic fish hook being cast in the upper atmosphere, auroras put on an impressive display above northern Norway in mid-March as comet Pan-STARRS passed overhead.
According to some sky-watchers—particularly those in the far North—auroras add to the sounds of nature. A recent study may shed light on how the illuminating phenomena produce faint clapping sounds. (Read more about the sounds of the northern lights.)
Cornucopia of Light
The night skies above the forests in Kiiminki, Finland, (map) don green for St. Patrick's Day as the northern lights put on a show.
"Once the sky was dark enough, it was filled with the most amazing auroras," said Thomas Kast. "It was as if Lady Aurora opened a restaurant with an all-you-can-eat buffet and she made sure no one stayed hungry."
Painting With Light
Like the broad strokes from an artist's brush, charged particles paint a spectrum of colors across the skies over a frozen river in Iceland in a picture taken February 15.
Photographer Kristin Jonsdottir got lucky and captured not only the atmospheric light show, but also the planet Jupiter (bright dot, left) beside the famed Pleiades star cluster - located more than 400 light-years from Earth - in the same shot.