In the novels of Arthur C. Clarke, the name originally given to the giant black monolith discovered at the Lagrange point between Jupiter and Io. The name was rather inappropriate, as the half-kilometer-long monolith displayed no signs of a magnetic field, and it was millions of miles away from Tycho Crater, where TMA-1 was discovered. Many people referred to it as "Big Brother" (as in "TMA-1's big brother") or as simply "the Monolith"; the Russian crew of the spacecraft Leonov dubbed it "Zagadka."

The first human to visit this monolith was Discovery Mission Commander David Bowman, in 2001; he apparently vanished shortly after venturing towards it in a space pod, leaving behind only the enigmatic radio message, "My God, it's full of stars!" The monolith transported him far beyond human understanding, to a place where he was "reborn" as a being of energy; it returned him to the solar system in 2010. Shortly thereafter, TMA-2 itself disappeared, only to be found a short time later in Jupiter's atmosphere, where it was continually replicating itself in order to increase the planet's density and ignite a fusion reaction to turn it into Lucifer. A virtual twin to this monolith would shortly thereafter appear on the surface of Europa, only to be overturned and possibly damaged when Mount Zeus struck the moon sometime between 2028 and 2038.

Source: Arthur C. Clarke, 2001: a space odyssey, 2010: odyssey two, 2061: odyssey three