What an unbelievable display last night! Awesome does not even come close. I have never before had to stop observing because the aurora was drowning everything out. On many occasions the limiting magnitude was down to around 2. Even when the aurora was quiet, it was like the sky was covered with high cirrus cloud.
I first noticed the display shortly before 8.00pm CST (2.00am UT). I was outside conducting and observing session for a group of students, when I noticed that the sky seemed to be brighter. A minute or so later, an arc of greenish light became visible to the north, about 15 degrees above the horizon. I called the attention of the students to this display, and as we watched the aurora rapidly brightened, the arc broadened and moved higher in the sky, numerous rays began to appear, and then bright red patches started appearing on the upper edges of the display. It was immediately obvious that we were in for a major display.
By 8.15pm, the display had reached the zenith and was showing numerous bright red and green rays as well as diffuse glows. A bright green curtain was also visible to the north-west. By 8.25, the display had quietened down somewhat, and appeared as a diffuse glow covering much of the sky, with the occasional bright ray.
Shortly before 9.00pm the display intensified and appeared as numerous bright red and green rays streaming from near the zenith, in addition to the diffuse glows. At this stage the glows were reaching to within 20 degrees of the SOUTHERN horizon. Also the display had become so bright that the students had to give up on their telescope observing as deep-sky objects were drowned out. This surge lasted about 25 minutes. An even brighter surge occurred close to 10pm, and even though the moon had now risen, it made little impact on the display.
The most spectacular time for me was at 12.42am CST (6.42 UT). At that time the Pleiades was close to the zenith. The aurora suddenly intensified and the whole sky was covered with intense red rays streaming from the Pleiades and reaching down to even the southern horizon. At times bright green rays would intermingle with the red, and on 2 occasions VERY bright arcs appeared close to the radiant point. These arcs spread outwards along the rays, moving away from the radiant point. It was like you were racing toward the Pleiades. My jaw was somewhere below ground! It was impossible to do anything apart from sit and stare! This intense period lasted about 20 minutes, after which the display quietened down to “only” a bright green glow with large patches of red and numerous, moderately bright rays.
Of course by the time this surge occurred I had run out of film! 🙁 However I cannot complain. It was a privilege to be able to observe it.
I finally ceased observing at 3.00am. By this time the aurora had quietened down considerably. It was still visible as a diffuse glow over much of the sky, down to about 35 degrees above the southern horizon. To the north, there was a greenish arc about 25 degrees above the horizon. no red glows very visible.
Maurice Clark, 6 Nov 2001
These pictures were taken on 29 Oct and 5 Nov, 2001, by Maurice Clark at
Goodsell Observatory, Carleton College, in Northfield, Minnesota, USA
(Latitude 44 degrees, 29 minutes N)