The footage was captured at the Glacier Bay National Park and Reserve. The park posted the video to its Facebook page and explained that the mirage is called a "Fata Morgana". The strange dome-shaped object in the video is actually your brain being tricked into seeing a distorted version of an island. A Fata Morgana is a mirage that appears just above the horizon and can significantly distort an object that's already there. Glacier Bay National Park and Reserve explained on Facebook: "Fata Morgana is a mirage seen within a narrow band on Earth’s horizon. Islands in glacier bay turn to UFOs or the flying Dutchman with a little imagination and a pinch of cool science! When air of different densities meet, the air in Earth’s atmosphere acts as a refracting lens, creating the mirage effect we see.
Motion activated security camera (Uniden-AppCam) mounted on shed activated and sent alert to phone. On inspection it shows a clear UFO Fastwalker. UFO shows up in only one single frame This single image of a UFO proves that crafts equipped with advanced technology flying through the sky that are not visible to the naked eye due to their enormous speed. source: www.mufon.com