October 2003 Auroras

In late October, 2003, two years after the solar cycle maximum, the Sun once again became highly active. A large sunspot group known as 486 formed and produced several violent flares. One of these, ranked X17 (one of the most powerful ever seen) occurred on 28 October while if was facing directly towards Earth. A large coronal mass was ejected at a very high velocity, taking only 19 hours to reach us. This produced a short but spectacular aurora with visibility extending well into Colorado.

Red and green curtains. As with other auroras seen at our relatively low latitude, red was the dominant color. Red is not commonly seen because it is associated with only the most energetic events. But those are precisely the events required to push the auroral arch as far south as Colorado, so it isn't surprising to see it here. All images are 20 second exposure, 28mm lens, Kodak Elite 100 pushed to 200.

Lost Dipper. The Big Dipper, tipped upwards, is nearly lost in the intense glow at the left of this arch.

Fine Structure. More so than with auroras I've seen previously, this event showed a great deal of fine structure. The pictures don't fully capture this because the 20 second exposures blur it out somewhat. Visually, these structures were quite dynamic, shifting position over a period of only a few seconds.