Perfectly round, extremely bright craft appeared over central Utah traveling from south-west to north-east.Craft appeared near the south-west horizon and appeared to be traveling too fast to be a plane. We watched it pick up speed on a constant bearing to the north-east. At first the craft appeared to be a bright chrome like light. We put binoculars on the craft and it was so bright it was hard to keep looking at it. Before it reached directly overhead, it became a dull orange. At first we believed it to be an experimental aircraft from Nellis, Hill, or one of the other Air Force bases near our state. When the craft was overhead, it slowed momentarily, and then picked up speed at an unbelieveable rate until it reached the horizon in the north-west. There was no sound and no contrail visible. I have seen other such craft while camping in Utah's deserts over the years, this one was faster than anything I or my wife have ever witnessed! When it headed for the north-west, it accelerated so fast it was hard to keep binoculars on it.