This may be the most amazing shot of the northern lights, yet. Check out the way they're moving — that's no timelapse, this video was shot in realtime.
So, why are the northern lights moving so quickly in this shot? It has to do with an increase in activity on the sun. Phil Plait over at Bad Astronomer explains:
We can get aurorae from just the solar wind without a big storm from the Sun, but when there is a storm the aurora are much brighter and more active. The shape of the aurora seen from the ground depends on the shape of the Earth's magnetic field. It can form long ribbons or sheets which look like curtains of light in the sky, or it can just be a diffuse glow. The shape can change as the solar wind's magnetic field interacts with the Earth's field, and it's usually slow and stately. But it can also happen very rapidly, as you can see in the video. Then the aurora is like a living thing, writhing and shimmering.
Though there wasn't enough activity for a geomagnetic storm this time, there was still plenty to create the amazing display you see above.