Bizarre expanding light halo seen by Hawaii webcam

The Bad Astronomer writes: "A webcam mounted at the CFHT observatory in Hawaii caught a strange, expanding halo of light on the night of June 22. Announced on the Starship Asterisk forum, readers quickly honed in on the likely culprit: the terminal charge from the third stage of a Minuteman III missile. Very similar to the Norway Spiral of 2009, and scientific sleuthing at its best!"