Large blue/green circular object with same colored outer ringWe were driving to Calif and were about at the 110 mile marker in Arizona (approx 110 miles from calif going west). We were startled by an intense green light to the south, it was shaped liked saturn (large circular center with a single wide outer ring around it) blue/green in color. It was extremely bright, lit up the entire area. There was no sound, it moved at an extremely high speed from the east to west, as it got about even with us it dropped below the mountain range to the south.