by Marek Cichanski
I'm in Ann Arbor, Michigan at the moment, and I managed to get out for an observing session on Saturday, where I saw a remarkable aurora!
I went to a public night put on by a group called the University Lowbrow Astronomers. I'd heard of this group when I was growing up in Ann Arbor, but I never went out to their observing site, and I'm sorry I didn't. Although it's got some fairly substantial light domes (I'd put it roughly between MB and Coyote in this respect), it's a nice peaceful site on the outskirts of town. Some years ago, the club restored a 24" Cassegrain telescope that had originally been built in the 1930s, and it's housed in an observatory with a roll-off roof. A radio telescope operated by the U of M is located nearby.
Many of the local amateurs were at a star party in Pennsylvania, so I was one of the more experienced observers there, and helped a couple of newcomers set up their scopes and find some objects. As astronomical twilight set in, around 9:30, it seemed as though someone was taking flash pictures, with their flash unit just out of direct sight - say on the other side of a car twenty or thirty feet away. After a few minutes, there seemed to be a brighter flashing somewhere out of sight, like fireworks going off a few kilometers away, but shielded from direct view by trees to the north. I noticed a shaft of light that seemed to be projecting vertically upward into the sky, like a searchlight at the opening of a new store. Within a minute or so, it was joined by a host of others, and we realized what was going on. From the NE through the NW, shafts of light arched up towards the zenith. A roughly horizontal band formed at an altitude of about 15 degrees, and then patches of red started to develop. For example, on of them roughly occupied Cassiopea for a while.
The whole thing didn't last much more than 15 minutes or so. While I'm glad that I don't have to add regularly auroral displays to my list of skyglow problems, it was pretty neat to see one this good. I never saw one like that when I lived in Michigan, and most of the people there couldn't remember many that were like this.
Hope everyone's having fun in the Bay Area. Soon I'm going to put myself in a place where observing is REALLY difficult - I'm going caving in Kentucky this weekend. I'll be back in the Bay Area on the evening of the 18th.