Sometimes bright lights in the sky really do need explaining, as was the case in San Francisco on Saturday when a Navy missile test caught observers off-guard. The picture above of the unannounced launch, taken by photographer Abe Blair, shows why some individuals might jumped to the conclusion that it was aliens tearing it up above the Golden Gate Bridge. More than a few YouTube videos from eyewitnesses identified the missile test as a UFO (including members of the Kardashian clan), but the Navy soon confirmed that it was an unarmed Trident II D5 missile launched from an Ohio-class nuclear submarine.

According to a report from Slate, the launch was seen as far afield as Northern California, Nevada, and Arizona. These missile tests are fairly common, but not usually in metropolitan areas at night, where they're far more visible. The plume from the rocket in this case looks especially large because it's high up enough that gas from the exhaust has spread out easily (no air resistance), while also being lit from behind by the rays of the setting Sun over the horizon. For a longer look at Saturday's launch, you can also check out this time-lapse video from the same location: