Animation of the discovery images of S/1999 U3. Each image in the loop sequence of 3 images is an 8 minute exposure (are shown is approximately 20 seconds of arc on a side, or 300 000 kilometers at the distance of Uranus).The images were taken about 2 hours apart. The satellite is moving down and to the left on this image, other "moving" targets are cosmic rays (noise) and do not move in a fashion consistent with a satellite of Uranus.