My wife and I were sitting in our campsite at Twin Shores campground in PEI. My wife was facing me and it moved into her field of view over my shoulder and she yelled "what is that?" and pointed at it. I had no idea what it was, it looked like the sun at sunset but you could look right at it without it bothering you. I hold a commercial pilot license so have a pretty good grasp of heights and speeds of objects in the sky. It moved across from the right of the sky to the left and decelerated at a perfect constant rate then stopped. I would say it was about 500 ft in the sky and was probably 5 times wider than a Cessna 172 which would be over 180 feet across. After it stopped moving it took off directly away from us and moved up in the sky at a 45 degree angle until it disappeared from view. This thing was moving very fast. I have never seen anything like it. Notice the smaller circle at the top. We were both not afraid more mesmerized than anything.Unfortuantely I zoomed in too tight to get a comaprison of the tree tops etc.