It around 10:15 or so when I went in my backyard with my dog, noticed a very low cloud overhead, the only cloud on a still, clear Lubbock night. It caught my attention by being so low and seeming to have a misty quality with spirals of mist coming downwards. It reminded me of steam coming from a low creek on a hot humid summer night. I watched intently 10-15 seconds wondering what could possibly cause such a cloud when my dog ran up to me. I bent over and was petting the dog for only seconds when a bright light seemed to go across my eyes in one direction and then again in another in rapid succession. I looked up and directly overhead was a light. It was passing overhead so I turned 180 degrees and then I could see the entire length of the light, it was greenish white showing through the misty cloud. I was totally awed by the object. It was so low in the sky, a few weeks before hot air balloons had passed overhead at a low altitude and I believe this cloud and object was just as low. It was a solid light in the shape of a boomerang and I would say at least 1/2 mile wide. Totally silent moving at a high rate of speed enveloped in a wispy cloud. I watched it as it passed over my house, it was out of sight in only a 5-6 seconds or so. I stood dumbfounded for a few seconds trying to process what I just saw and then ran to the front of my house, jumped in my car. I live near a highway and was able to go towards the cloud for only a couple of minutes before it was out of sight moving towards the SE traveling in a straight line.