SIGHTING REPORT UFO sighting at London

Transparent disk

Left area of nuclear power plant very rapidly.

On Oct. 4, 2001 I was on a flight leaving Heathrow airport in London. Our flight left at around 9:30 am London time. The plane was in a steady climb. Our altitude was only around 10-15 thousand feet. We had just passed above the puffy sparse clouds that were in the area. I had two windows available next to my seat. I was looking out the forward window, looking as close to straight down as I could, I saw some sort of movement between the ground and the puffy clouds right below us. As I looked closer I could see that the ground was being distorted as this object passed above it. It caused a wavy appearance to the ground. Looking closer I could see a definite line where the distortion ended, it looked like a huge contact lens, or a clear plastic disk. I watched this thing pass under three or four clouds and always continue on the other side. I could only track it so far because of the small windows on a 777. I then leaned back and could still see it in the window that was in line with my shoulder. It was traveling in the opposite direction as the airplane, and going maybe three times faster than the clouds passing below us. I watched it until I could see it no more due to the small windows. Right after it was gone I noticed directly below us a nuclear power plant. This object was traveling away from the power plant. I believe this was not a reflection as it was observed from two different windows. It took me a few seconds to realize that what I had seen was really there. It was.
I am currently having my son who lives in London for a short time longer, find out where the nuclear power plant is located so as to figure out our position and what direction we were flying.