We were going north on Usery Pass Road out of Mesa Arizona. Suddenly we saw a brilliantly colored ball with a tail to our right which would have been the northeast. It was very close and low to the ground. We expected to hear a sound and see smoke or something. But we saw nothing and heard nothing. The round ball was very close to the ground when we first spotted it and was closer to the ground when it disappeared behind a jutting piece of ground. We were in the mountains. We think it was about 1/2 mile away from us. An amazing sight. We were glad there were two of us so that we knew it wasn't our singular imaginations.