L-shaped and light-colored object(s) moving generally from NW to SE late at night.This object(s) moved across the clear night sky on a line from the Constellation Cassiopedia to the Constellation Orion. It had no lights but was apparently light colored and reflecting lights from the city. As best as I could tell it was L-shaped with the long arm parallel to the direction of motion. It also seemed to have a second short arm a short distance behind the leading short arm. It may have been a flock of light-colored birds but it seemed very rigid (no individual motion), rapid, and not a V-shape as I usually see during the day. I think it was silent but couldn't tell as a very busy street is only several houses away. It happened directly above my house.