White light makes a turn and disappearsI live about eight miles west of the Madera Municipal Airport. I earned my private pilot's license at that airport. The approaches for the Madera airport and the Fresno Air Terminal beyond it are directly over my house for aircraft coming from the Bay Area.In the evenings, I see aircraft with their landing lights on approaching from the northwest and heading towards the southeast. As they get closer, you can hear their engines, see the strobes, and finally see the red and green navigation lights when they are directly overhead.Fifteen minutes ago, I was out in my yard when I saw what I thought was a light aircraft with its landing lights on approaching from the northwest. The sky was partially overcast with wispy clouds. The light seemed to be going at about the same speed as a light aircraft and was at about 8000 or 9000 feet altitude.I watched it, waiting to see the strobe as it got closer and listening for engine sounds, but it remained silent, and there were no visible strobes or navigation lights. Then it began a slow, wide turn to the south. It's hard to describe, but it almost seemed to slide. The color of the light was almost the same color as a landing light.After the 90 degree turn, landing lights would not have been visible on an airplane, but this light remained constant. Then it began to speed up, and it either gained altitude, or the light faded out. I don't know which, but it just disappeared.I know some people will say it was an airplane, but it wasn't. When it was overhead, I should have seen a strobe and the red and green navigation lights, and it should not have had white lights facing backwards. Also, it's possible to hear a jet or propeller engine at that altitude, and it went from a constant brightness to a dim light to nothing in about five seconds time. It wasn't an airplane.