I was sitting in the hot tub with my wife watching a completely cloudless and calm sky. It was 9PM so we had a great view of the starts. I noticed movement at the northern horizon in the trees and an object glided into view. I alerted my wife "look at that!!!" and pointed for her to see. She observed with me the entire time. It was a black and gray object, shaped like a HUGE broad boomerang, soaring silently over our house. The colors reminded me of black outline with a gray/dark tan inner stripe. It moved from north out of the treeline overhead to the south where it promptly disappeared. Silent, smooth and without lights. I watched it glide overhead and followed it as it flew. I attempted to continue watching it as it progressed south but it just vanished from sight. Cool.