Alright – I was just pointed by a commenter on flickr (who commented on my simulation below) to a further article here which indicated that the “Comet” I saw was a rocket upper stage venting gas. It created a “fan shaped” cloud which is exactly what I saw. Several people on this thread also saw it. I’m not sure if anyone got an image yet, but if I find one, I’ll post a link. So it wasn’t a cloud after all…
Update: Spaceweather.com has images and VIDEO!
