I was walking my dog. I looked up in the sky and noticed a boomerang-shaped metallic object flying low, it made no noise as it moved. There were no lights but I could still tell it had a metallic aura. The object was flying back and forth then left to right. It held its position for a few seconds after about 10 seconds into watching it. All of a sudden it started flying at a really fast rate of speed. I could no longer see it within 5 seconds.