context: To Richard Strauss' tone poem "Thus Spake Zarathustra," the title sequence shows the sun rising behind the Earth, which is behind the moon.The Dawn of ManIn a sere African landscape, a group of ape-like hominids and some tapirs compete for the meagre green plants. A leopard attacks an ape. While one group of apes is drinking at a waterhole, another group approaches; the two groups scream at each other and one party is driven off. At night the apes huddle in fear among the rocks. In the morning a tall, thin, rectangular black monolith stands among the rocks. The apes are excited but touch the object and calm down. (Soundtrack: György Ligeti's "Requiem.")An ape (Daniel Richter) lifts a femur bone from a skeletal pile and realizes it makes a fine weapon. (Soundtrack: "Thus Spake Zarathustra" again.) The ape realizes that it can destroy other bones with the club. Three turning points in evolution happen simultaneously: proto-humans learn to kill with weapons, to hunt using weapons and eat meat, and to walk upright. Club-carrying apes approach the group that drove them away from their waterhole. The club-carriers bludgeon the other group's alpha male to death and chase off the rest. The victorious alpha male throws his club and it spins into the air.TMA-1, or the Monolith on the Moon(No title card introduces this section of the film)The spinning bone segues to spaceships above Earth. A Pan-Am space shuttle approaches a large spinning space station, its revolutions mirroring those of the ape's spinning bone. As a single passenger dozes in his seat, a flight attendant with Velcro shoes recovers his floating pen. The shuttle pilots carefully match rotation and steer the shuttle into the station's central docking bay. (Soundtrack: Johann Strauss' Blue Danube waltz.)Dr. Heywood Floyd (William Sylvester) meets an old friend in the arrivals lounge. They go through a voiceprint security check in which Floyd identifies his destination: the moon. The men chat; Dr. Floyd has a connecting flight in one hour. Floyd calls home from a video payphone booth and talks to his young daughter (Vivian Kubrick), whose birthday is the next day. He's sorry he'll miss her party but asks her what sort of present she wants; she asks for a bush-baby. The cost of the call is $1.70.In the Hilton lounge, Floyd stops to chat with some Russian scientists on their way back to Earth. When Floyd mentions he is going to Clavius, the Russians say no one has had contact with Clavius for 10 days and there are rumors of an epidemic. Floyd says he cannot discuss the matter and goes on his way.A smaller spaceship approaches the moon. A flight attendant serves food trays that consist of many compartments of liquid nourishment labeled with pictures -- carrots, peas, and so on. Floyd sips his meal, talks briefly with one of the flight officers, then contemplates the long list of instructions for the zero-G toilet. He watches the moon approach. The craft lands in a domed landing pad then descends underground to the main complex, once again to Johann Strauss' stately Viennese waltz.Floyd is introduced to a group of people in a conference room. He congratulates them on their discovery. He tries to explain the need for secrecy and the epidemic cover story. Floyd has come to get more facts and write a report for "the Council."A shuttle skims over the lunar landscape. Inside, Floyd and two scientists enjoy sandwiches and review the findings. A magnetic object was found and excavated. They're not sure what it is, only that it was deliberately buried four million years ago.At the dig site, a tall, thin, black rectangular monolith -- identical to the one the apes encountered -- is examined by six people in spacesuits. (Soundtrack: György Ligeti's "Requiem" again.) As they pose for a photo the object emits a loud, high-pitched noise and the astronauts grab their heads in pain.Jupiter Mission 18 Months LaterA long narrow spacecraft moves through space, its parabolic antennae pointing backwards. In the crew compartment, Dr. Frank Poole (Gary Lockwood) jogs around the artificial gravity wheel. Along the narrow corridor formed by the edge of the wheel, he runs past work stations, communications equipment, and five large, coffin-like life support chambers with glass covers. Two are unoccupied and three hold white, sarcophagus-shaped pods containing hibernating members of the crew.Frank is joined by Commander Dave Bowman (Keir Dullea). The two men have a meal and watch a BBC news video from earlier that day. The news report is about them and their ship, the Discovery, 80 million miles from Earth. The report mentions the three astronauts who are in hibernation to save air and food; they will be needed at the destination for a survey. The sixth member of the crew is the HAL9000 computer, which can talk and mimic the human brain. The newscaster interviews Dave and Frank together and then speaks to Hal (Douglas Rain), who states he is foolproof and incapable of error.Frank catches some UV rays on a tanning bed and watches a video birthday greeting from his parents. Hal also wishes Frank a happy birthday. Frank and Hal play chess -- Hal wins. Dave sketches and shows his artwork to Hal. The computer expresses some concern about the mission and secrecy. Hal then announces there is a problem with the AE-35 unit and it will fail with 100% certainty within 72 hours. Dave and Frank discuss the problem with Mission Control; they need to "go EVA" (outside the ship -- extra-vehicular activity) to replace the unit. Dave goes out in a spherical EVA pod to the parabolic dish antennae in the center of the long ship. He leaves the pod and swaps out the black box from a service panel.Later the two astronauts scan the removed AE-35 unit but can't find any defects. Hal suggests putting it back in service to let it fail. Mission Control believes Hal has made an error because their HAL9000 unit, a twin to the one aboard Discovery, finds no flaw in the AE-35. Hal says that similar problems in the past have always proved not to be his fault ("It can only be attributable to human error") and denies any chance of computer error. Dave and Frank go to a pod to have a private chat under the ruse of looking at a communications problem.Dave turns off all the pod's communications switches and the two men share their worries about Hal. If the AE-35 unit doesn't fail as predicted, the astronauts decide to disable Hal's higher functions without disturbing the automatic ship control functions, which Dave says will be tricky to do. Dave also wonders how Hal will react, because no 9000 unit has ever been disconnected before. Hal can see the men through the pod's window and reads their lips.This time Frank goes out in the EVA pod. As Frank approaches the dish assembly the pod sneaks up behind him. Suddenly Frank is spinning off into space fumbling for his air hose, which is disconnected, and the pod is drifting in the other direction. As Frank tumbles away, his voluntary movements slow and stop. Dave goes to the pod bay as Hal says he doesn't know what happened. Dave uses a pod to recover Frank's body. While he's away, a computer malfunction alert goes off and the life signs of the three hibernating astronauts flat-line. A display reads "Life functions terminated." Hal refuses to open the pod bay doors for Dave, explaining that he knows Dave is planning to disconnect him because he was able to read Frank and Dave's lips when they discussed it. He says the mission is too important to allow humans to jeopardize it. Dave says he'll return to the ship through the airlock; Hal replies that Dave will find that difficult without his helmet -- which, indeed, Dave forgot in his hurry to go after Frank. Hal ends the conversation.Dave releases Frank's body and maneuvers the pod to the emergency airlock hatch. He uses the pod's arms to open the door, then lines up the pod's hatch with the opening. Dave holds his breath and jumps over to the ship, where he's tossed around by escaping air before he's able to close the hatch. Now in a helmet, Dave goes to the computer room and climbs into an access compartment. Hal pleads for himself as Dave pulls crystals from the memory center. Hal's voice gets lower and slower as he sings "Daisy Bell" (Daisy, Daisy, give me your answer do, I'm half crazy all for the love of you), and fades out as he is completely shut down. (Hal's performance is a nod to a speech synthesis project at Bell Laboratories in which an IBM 704 was programmed to sing the same song.) Suddenly a video screen comes on and plays a recording of Dr. Floyd explaining the secret purpose of the mission: "This is a prerecorded briefing made prior to your departure and which for security reasons of the highest importance has been known on board during the mission only by your HAL9000 computer. Now that you are in Jupiter's space and the entire crew is revived it can be told to you. Eighteen months ago, the first evidence of intelligent life off the Earth was discovered. It was buried 40 feet below the lunar surface near the crater Tycho. Except for a single very powerful radio emission aimed at Jupiter, the four-million-year-old black monolith has remained completely inert. Its origin and purpose are still a total mystery."Jupiter and Beyond the InfiniteClose to Jupiter, another black monolith floats among the many moons. We hear György Ligeti's "Requiem" once again. Bowman leaves the Discovery in another EVA pod. As the monolith and moons align, a psychedelic light show begins and the pod enters a wormhole to the music of Ligeti's "Atmosphères." Dave sees a series of oddly-colored landscapes as if he was flying over them. The pod ends up somewhere in time and space in a bedroom with a luminous white floor and furniture in the style of Louis XVI. Dave gets out, now a trembling grey-haired man. Next door in a similarly styled bathroom, Dave looks at himself in a mirror. Back in the bedroom someone is sitting at a table eating. It's Dave again, now much older and dressed in a dark velour robe. Old Dave has a drink of wine; the glass falls to the floor and breaks. Another man lies sleeping on the bed. It is a still older Dave, who stirs and raises an arm. The black monolith appears in the center of the room. Dave is transformed into a fetus in a sac. Floating in space, the large open-eyed fetus -- the Star Child -- gazes at the nearby Earth. Soundtrack: "Thus Spake Zarathustra."
question: What reveals the existence of monolith on the moon ?
answer: An excavation team.