Bright blue ball of light over alva, ok.I was working on a drilling rig 3 miles north of Alva, ok. The motorhand and I were asked to move our trucks to allow a tank truck to enter location. We parked close to one another and got out about the same time, we both seen a big bright blue ball of light just in the clouds. There were only a few stairs visible because of the clouds that night. It was as big as the moon and traveled faster then any jet or plane that i've ever seen, then disappearde.