 The phrase "My God, its full of stars" was not a part of the film  2001, but was a part of the novel. In the novel, the "star gate"  monolith was found on the surface of Saturns moon Japetus (or  Iapetus), rather than floating in space near Jupiter. As Bowman  flies over the monolith, it suddenly changes from a towering slab to  an infinite tunnel. As this happens, he utters the final phrase:  "The things hollow! It goes on forever, and... oh My God, its full  of stars!"