Light in sky..then gone | Mike D

Mike D
Location of photo
Lat: 42.716008 Long: -71.199364
Date/Time of photo
3/22/14 21:12:54 + 21:13:05
Canon Rebel T3i 2 shots of a time lapse shoot. Shots were taken at an interval of 12s I only show the one shot here that shows the bright light.
I've been shooting night time lapse photos for the last week but have never seen something like this where a light appeared then vanished in less than 12secs....does anyone know what this might be? ...Thanks for viewing, Mike