Approximately 10:30 pm, I was standing in the back yard, enjoying the stars. It was a perfectly clear sky with no clouds at all. Suddenly a small cloud appeared in the southeastern sky. I was focused on the cloud because it seemed to just manifest out of nowhere. Instantly, a light flew across the sky, moving faster than anything I've ever seen. It stopped behind the moon. Before I could say a word, it move from behind the moon, as fast as it got there, and went out into space, disappearing into the night. This was the only sighting I've ever experienced. It moved like a photon. I know our government has secret technology, that the public knows nothing about. I doubt they have anything close to this. I believe they created the cloud to hide behind. Perhaps they came up from a place on earth, and needed a place to hide. I stepped away to get my binoculars during time the cloud appeared. So I'm curious what else I missed. I live in Texas and was visiting the Oglala Lakota Reservation for a few days after having spent a week in the Black Hills.