With a quick look at the image, one could get the impression that there is an alien spaceship flying above the Paranal Observatory.
However, it is just the Moon. A long-time exposure was chosen for this images, which therefore reveals the motion of the Earth
around its axis not only by the trails of the stars, but also by the much brighter trail of the Moon.
Not an UFO | ESO
http://www.eso.org/public/images/imgp1447-2-cc/