2001: A Space Odyssey Wiki
2001: A Space Odyssey Wiki

The excavation site of TMA-1.

Tycho Monolith, designated TMA-1 (Tycho Magnetic Anomaly One), is a large black crystalline monolith found on Earth's moon in Arthur C. Clarke’s 2001: A Space Odyssey and its film adaption.

The Sentinel[]

TMA-1 is fashioned to the exact proportions of 1:4:9, and is dated to about four million years old. Its artificial construction suggests that it was left behind by “monolith aliens”. The concept was inspired by Arthur C. Clarke’s 1951 short story, The Sentinel.

2001: A Space Odyssey[]

The Tycho Monolith was first discovered in 1999. American survey satellites discovered a strong magnetic field near the crater Tycho. It was first assumed to be a giant nickel-iron meteorite, but not even that could produce such an intense field. Excavation at the site unveiled the three million year old black monolith which was buried 20 feet below the lunar surface. This Monolith was officially dubbed Tycho Magnetic Anomaly One, or TMA-1.


Dr. Floyd reaches out to touch the monolith.


"After three million years of darkness, TMA-1 greeted the lunar dawn."

A cover story was produced by the National Committee for Astronautics, as the knowledge of TMA-1 would most certainly cause some cultural shock. The cover story was that an epidemic of unknown origin had broken out at Clavius Base, though most members of the NCA found this cover story to be rather embarrassing. All communication with Clavius had been cut for several days, and a Soviet shuttle had been denied an emergency landing at Clavius. Dr. Heywood Floyd, chairman of the NCA, was taken to Clavius Base to investigate the monolith. Soon after arrival, he was shuttled to the TMA-1 excavation site. When he arrived, he approached the black enigma and reached out to touch it. The crew then gathered together for a photograph to be taken of them in front of the monolith. Soon after the picture was taken, the sun rose up from behind the lunar horizon. The Tycho Monolith gave off a single, very powerful, radio emission, aimed directly at Saturn (Jupiter in the film).

"After three million years of darkness, TMA-1 greeted the lunar dawn."

Scientists hypothesized about what the purpose of the monolith might be. Several theories were put out, such as the monolith might be a storage unit, or perhaps some solar-powered energy generator. However, the most plausible theory, and perhaps the most frightening, is that the monolith is some sort of alarm, and it has been triggered, sending a message to the alien intelligence that created the Tycho Monolith, and alerting it to our presence.


By the year 3001, the Tycho monolith had been moved to the United Nations building on Earth, where it served as a reminder that mankind is not alone in the cosmos.

Though the monolith could be approached without incident, anyone who did so found that their fingers skidded across the absolutely frictionless surface, repelled from the monolith by some invisible barrier, making it impossible to actually touch the monolith itself.