Auroral All-Sky Dance

Here is nearly two hours of auroral dancing compressed into 25 seconds.

This was the “all-sky” aurora of August 5/6, 2011, widely seen over North America but perhaps (from early reports) best from the western half, especially Canada, favoured for Northern Lights due to our latitude.

I shot this with the 8mm fish-eye lens and the Canon 5D MkII. The movie consists of 255 frames, each 24 to 30 seconds in exposure duration, taken one second apart. ISO speed was 1600 and aperture f/3.5. The playback frame rate is 10 fps.

This display was quite chaotic, without the graceful rippling curtains present in many displays, but rather huge patches of sky turning off and on. This is typical of an aurora in the declining part of the storm — it had already been raging for several hours by the time it got dark here in Alberta.

Nor was the display very bright, so the longer exposures needed to record it well further blur any fine motion. Nevertheless, you get a good idea of the intense activity this aurora displayed. The magnetosphere was jumping last night!

— Alan, August 6, 2011 / Movie © 2011 Alan Dyer