Andrei Penescu

The northern lights shimmer over Kangerlussuaq in Greenland on Feb. 27. "Out for about two hours in -36 degrees Celsius until my fingers gave up, but what a nice show!" Andrei Penescu told SpaceWeather.com. "I didn't get out too far from the town, and had a lot of light pollution, but the aurora was very bright."

A "crack" in Earth's magnetic field has opened the way for yet another thrilling display of the northern lights near the top of the world.

We're in the middle of an upswing in the sun's 11-year activity cycle, leading up to an expected peak in 2013. If solar storms get too intense, there could be a heightened risk of outages in satellite communication and electrical grids. But fortunately, the only significant effects from the solar outbursts so far have come in the form of heightened auroras, occasionally ranging as far south as Nebraska.

Auroras arise due to the interaction of Earth's magnetosphere with electrically charged particles streaming from the sun. That interaction energizes atmospheric oxygen and nitrogen in the ionosphere, causing ripples of greenish and reddish light between 60 and 200 miles up in Earth's polar regions.

SpaceWeather.com's Tony Phillips reports that the interplanetary magnetic field tipped south this week and opened a crack in our planet's magnetic shield to fuel a minor G1-class geomagnetic storm. The Space Weather Prediction Center said the storm was sparked by particles sent out from the sun during an eruption last Friday.

You can see the atmospheric physics at work in the picture above, captured by Andrei Penescu in Kangerlussuaq, Greenland, on Feb. 27. Fittingly, Kangerlussuaq is home to the Sondrestrom Upper Atmospheric Research Facility, a project that studies the aurora and other atmospheric phenomena.

Here are a few other photos from this week's auroral displays, plus two video extras. One is "Temporal Distortion," a time-lapse tribute to the aurora and other wonders of the night sky by Dakotalapse photographer Randy Halverson. It includes some of the auroral imagery we featured back in October, and features original music by Bear McCreary, the award-winning composer for TV shows such as "Walking Dead" and "Battlestar Galactica."

The other is David Peterson's compilation of time-lapse videos captured by astronauts on the International Space Station, including some primo views of the aurora from above. Here's what NASA's Mike Fossum, a former space station resident, had to say about the clip: "This is the best video I've seen from photos we took on ISS! Stunning!!"

Can't argue with that...

Aaro Kukkohovi

Finland's Aaro Kukkohovi saw an aurora of a different color burst forth on Feb. 27 in the skies over Lumijoki. "I've never seen anything close to this," Kukkohovi told SpaceWeather.com. "What a fantastic burst of energy - like something blew a hole into Earth's magnetic field just above us." For more from Kukkohovi, check out the gallery at the LumiSoft website.

AuroraMAX / CSA

The AuroraMAX wide-angle camera snapped this picture of the northern lights over Yellowknife in Canada's Northwest Territories early Feb. 27. For more from AuroraMAX, check out the project's website and Twitpic gallery.

More auroral glories:

• Rocket flies into the northern lights
• Northern lights appear to wash over ship in Norway
• The sun sends Earth a valentine
• Aurora extravaganza glows in space
• Planet looks back at the northern lights
• Auroras spark awe across the north
• Solar weather stirs up super sights
• Northern lights go way, way south
• Speed through Lapland's lights
• Beautiful blasts from solar storms
• Get a video view of Canada's aurora
• Slideshow: The best of the northern lights
• Cosmic Log's auroral archive