I saw a large round flying object moving very fast.I saw a round bright disk flying towards me. It was as large as a commercial airplane but it definitely wasn't an airplane. It was 15 or 20 ft. high with a round domed top. In the middle were objects that could have been windows. The bottom was a litle rounded but not flat. It seemed that the top may have been spinning. The sun was shining on it making it gleam. The object dipped, then reversed direction and started to climb headed towards Navajo Mountain. It started to rise very fast and disappeared from sight suddenly.