The Moon of the disc is in fact more of a moonlet, this small round rock orbits the disc once a day, sometime requiring one of the elephants to lift its leg to allow its correct path.
The moon is populated by Moon Dragons who feed on the local Moon leaf. These cause the moon's distinctive silver glow; however, one side of the moon always faces the sun, creating the burnt effect of its dark side.
The moon has been reached and explored by the brave crew of the Kite when it touched down on the lunar surface to re-supply the ship's air reserves. The first explorers on the moon were: Leonard of Quirm, who painted the disc; the Librarian; Rincewind the wizard, who ran around screaming for a bit, due to the height; and Captain Carrot, who claimed the moon in the name of all nations. This last action amused Lord Vetinari who remarked that 'he might even tell the other nations this'.