Thanks everyone! I was definitely thrilled with the show. Newcomers to this site might like to refer to an article I wrote a while ago on aurora photography:
http://community.the-digital-picture...ead.php?t=7457

Exposure is always a bit of a guessing game, but your histogram is the key to success. Pay special attention to the green channel (not just the overall brightness histogram). Adjust the shutter speed until the green is within 80% of the right side (full brightness). If the aurora is moving quickly, jack up the ISO until you can get the shutter speed to 4 seconds or less, to eliminate blur. The 24 f/1.4 LII is a fantastic aurora lens. I usually use it at f/2.0 to minimize coma (stretched stars) in the corners. And a full-frame camera is a huge benefit as well, in terms of wide angle view and low noise.

Happy shooting!