Spherical Light UFO traveling low, fast, and making quick turns.

Today, while taking a walk near my apartment near the canal on West Napoleon Street in Metairie, LA, I was looking to the west towards New Orleans International Airport expecting to see some airplanes in the distance.  After about a second of looking in that direction, I saw something flying much lower and closer than I was expecting to see.  The object I saw seemed to be about only a couple hundred yards away,  about 100 feet in altitude, 5-10 feet in diameter sphere of white light, and was going extremely fast (at such a low altitude: appx. 100 mph by my estimation) and making drastic turning maneuvers without making any noise.  After watching the object turn abruptly to start going over a residential area, the sphere of light “turned off” in the matter of a few tenths of a second. The object seemed to “be” light as I was not able to see any physical trace of the object after it disappeared. That was the last I saw of it.