Via Emily at The Planetary Society Blog, we get a firm explanation for this bizarre sight:
Not only is there that crazy spinning spiral, but the way its center opens up in what looks for all the world like sci-fi movie's "gate to another dimension" is just freaky. Of course, as with most initially unidentified flying objects, it had an explanation: with all the publicity since yesterday Russia was forced to admit publicly that the spiral was the highly visible and embarrassing failure of a test of its submarine-launched Bulava ICBM.The clip below (also from Emily) is a refined version of a theory that was floated yesterday, and has been more or less confirmed: a rocket spiraling out of control.
Not sure I buy it... I am not the first to say something along the lines of "I, for one, welcome our alien time lords." I might be the first to say that this is a much more impressive fireworks display than your typical version.