2004-09-22 - Petaluma, CA - Formation

6 small disks grouped together, changing formation, variable brightness, visible for 15 minutes, no clouds.

I was walking through a suburban neighborhood when I noticed 6 bright white objects flying closely together high in the sky (about 50-60 deg elevation). My initial impression was that they were birds. There is a local species of white crane, but I have never seen them flock like this. Moreover, these objects appeared to be much higher than the altitudes at which local birds fly. They were disk like and traversed the sky from SE to NW. At one point they circled. They changed formation, appearing as a straight line, a large "v", an "s" curve, 2 "v" shapes, and random grouping but still close together. They stayed together for the entire time I observed them (if they had been balloons, I would have expected one or more of them to drift away from the others). Their reflectivity/brightness varied as they moved across the sky, appearing very bright at one point, then almost disappearing before brightening back up.