There isa water mooncavebetweentheelephanttrunkand the legs, which is likea brightmoonfloatingonthe water. This is the famous scene "Water Moon of Elephant Hill".
The movie then jumps ahead to 2089, when two archeologists, Shaw (Noomi Rapace) and her boyfriend, Holloway (Logan Marshall-Green), discover some cave paintings with figures pointing to a planet or a moon.