In the first scene, an unknown vehicle is rushing through the alien planet's desert, raising a dust cloud. In the next scene it was revealed to be Robby the robot, who had welcomed the flying saucer's crew and invited them to the Morbius' home. Captain Adams and a couple of his mates accept the invitation and in a few minutes they rush through the desert by the same way back. However, this time the image is inverted. The big moon or the planet on the horizon is suddenly on the left side and all the rock formations have changed the sides. In fact, the departure scene is just the mirror of the arrival scene.
Departure (mirror of the arrival):