The Swan Nebula
A.k.a. "M17", "The Checkmark", "The Omega", "The Horseshoe" in the constellation Sagittarius. It looks more like a big white duck (to me) swimming from right to left. The light from this nebula left about 5700 years ago. The body of "the duck" is about 12 light years in length. This photo is a one hour exposure on Kodak PPF 400 film at f7.5, taken in cental Oregon.