Wife and i went outside to our backyard for her to smoke, started looking up at the sky due to possibility of orionid meteor shower. first 30 seconds outside, dark, faitly glowing, cloud-like wing or boomerang shaped mass flew directly overhead with almost no noise, just gentle swish like the wind blowing through the trees. speed was too fast for a formation of migrating birds. first thought it was a glider or other unpowered aircraft but had no marking lights, strobes or anything else an aircraft should have. mass moved from due north to south before losing sight of it. wife and i started discussing possible explanations, flock of birds, spotlights, aircraft but none fit with what we saw. after fifteen minutes, saw another one, further east and higher in the sky, again moving from north to south. over next hour plus, saw around 18, all moving in the same direction (n to s) at different altitudes. most looked like the boomeranges but some were too far away to get a proper shape, just could see the faintly glowing masses moving. masses were observed for approximately 6-10 seconds per. weather was clear overhead with clouds down south, temp around 60-65, with a light occaisonal breeze.