Monday, March 14, 2011


Another overhead view. This is one of my more favorite aurora photos that I took... not entirely sure why.

Exposure time: 4s
Aperture: f/1.8
ISO: 1000


  1. Composition-wise, I like the very off center placement of the arcs.
    Science wise, when you see a helical structure like that, do twists move up or down the rope (barber pole style) over the course of your watching them? If so, what kind of timescale is typical for such motion (twist propagation)?

  2. Weellllllll, I wouldn't really call it a helical structure. The greenest part that is curving along, probably remains at the same altitude. Movement and timescales are really weird things to generalize. The movement is always seeming new and different, at least for what your eye distinguishes as small-scale. Your eye can also pick out things that are moving quickly and things that are moving slowly. But then if you zoom in on the slow-moving parts with a powerful camera, you find some really fast motions that your eye couldn't quite distinguish. Sorry that this is not really a useful response :)