Extremely Bright White Light - No Sound

Was in the garden admiring how clear the sky was & noticed a very bright white light which moved overhead. This light was traveling silently across the sky. There were no flashing lights. It travelled faster than a plane but not as high or as fast as a shooting star. I watched it for about 30 seconds and the white light gradually began to fade and vanish. The object remained on a fixed straight trajectory and never changed direction or speed, even when the light began to fade till it disappeared completely.