This unusual phenomenon caught me completely by surprise, and by the time I managed to set up the camera the two objects were very low in the sky. The halo was gone, too. Still, I managed to record them as they drifted below Ursa Major.
My first thought was that it had something to do with Iridium 70, which should have been just about there at the time, but I was wrong :)
Photo details: Olympus E-510, ISO 800, 6 sec. exposure (could have been much better but I was in a hurry to get at least something).