One "Fireball" bright light, which ascended and descended rapidly +/- 100-200 Feet.

While flying in a general aviation plane at approximately 7,500 ft, heading north east from Yuma to Gila Bend (along V66) a bright fireball/ orb appeared. The light was estimated to be a mile or two away and approximately at the same altitude. The object appeared to be ascending and descending, at random intervals of several hundred feet. The object appeared unaffected by the strong winds occurring that particular night. The object stayed the same relative distance and it was hard to determine if it was moving or stationary (horizontally). After about 10 minutes the object faded out like a candle being extinguished quickly. ATC was notified by us for a possible converging traffic target and reported they had no other aircraft in the vicinity of 25 miles. Safety of flight was not impacted. Notice the pictures were taken in total darkness (almost midnight). But the object was bright enough to give the camera light to see the desert and surrounding area. The moon was also out, which aided.