White sphere seen from an airplane

Summary

A passenger reported observing a white sphere the size of a one-cent coin while traveling on a commercial flight on May 21, 2011. During the flight, the plane passed through a turbulent area, although the sky was clear and blue with a layer of clouds below. The witness noticed a large brown trail parallel to the plane and, near the wing, saw the bright sphere. He took photographs for about 15 minutes, between 19:55 and 20:10. The gray trail was the shadow of the plane's contrail on the clouds. The sphere was explained as an atmospheric optical phenomenon, similar to the Brocken specter, caused by backscattering of light in the mist droplets. This explanation suggests that the vibrations experienced by the witnesses were unrelated to the phenomenon. The disappearance of the sphere was likely due to the disruption of the cloud layer.