I was looking in the sky between 6:00AM & 6:30AM. I noticed what I thought was a star or planet. I then noticed it was moving and dismissed it as an aircraft. A few seconds later, it suddenly disappeared in a cloudless sky. I kept watching for a minute and it never reappeared. This was about an hour and a half before sunrise. It seemed puzzling for an aircraft to do this. Based on the "lights out", I have no idea what I saw.