My friend Roger and I were visiting buddy Pat in Benson, Arizona last night doing some dark-sky observing from his sky, at least dark compared to downtown Tucson! Pat had stepped into the house to assist wife Betty with a medical procedure when I noticed a brilliant light and expanding white cloud in the western sky. I've seen enough rocket launches from the west coast to know that is what we were seeing. They are particularly spectacular when launched at or shortly after sunset and the vapor trail and exhaust are illuminated by sunlight. In well-dark Arizona it can be an amazing sight!
I was already exposing with one camera on the telescope, so ran for the spare and clumsily set it up on a tripod, fumbled with settings, tried to focus on the distant lights of Benson and aimed to the already dimming cloud. It seemed to take 10 minutes to accomplish all that before my first exposure, showing the amazing expanding vapor cloud. It didn't take many minutes and the email chatter started among astronomers around the state (aren't cell phones amazing - even in our "remote" site!). Most agreed with my assessment, but Melinda at home confirmed later that the public along the west coast had jammed the media wondering what it was. Seeing my first frame above, you might think there was an incoming bomb exploding.
This morning I quickly performed some minimal contrast adjustments and sent them to our TAAA resident missile expert Jim O'Connor. He identified the blue cloud as the likely result of the 1st stage separating and ignition of the second stage. Of the 6 frames I got at approximate 1 minute intervals, frame 3 and 4 show a "puff" that might be the 3rd stage ignition, and the other plume he indicates may be the steering jets for aiming the warhead towards its target.
Finally this afternoon the notice came out: "The unusual light show observed last night from California and outlying areas was the unannounced launch of an unarmed Trident II (D5) submarine launched ballistic missile. The Trident was launched off of the southern California coast by the submarine USS Kentucky." So that's the story - Pat came out a few minutes later, disappointed he missed the whole thing! Below is a short time-lapse of my 6 frames on Youtube:
EDIT: I was thinking that at 600 miles, we must be about as far from the launch as you could be - but I'd be wrong! I got a message from some friends observing from near Portal, AZ who saw it (likely another 70 miles further east) and had dinner with a friend tonight who saw it camping from near the AZ/NM border last night. Looking at Google maps, that is close to the distance from Portal as well - well over 670 miles, depending on the exact launch point!