Marcus Manilius was a first-century Roman poet, who produced a work titled Astronomicon notable for describing the zodiacal constellations of the Roman world. Though his name is recorded in various forms, the spelling Manilius is used for this prominent crater near the centre of the Moon's nearside.
The crater Manilius dominates the eastern part of Mare Vaporum, the Sea of Vapours. To the northeast of the crater lie the Haemus Mountains, and beyond them the wide flat expanse of the Sea of Serenity. Some 39km across, Manilius is also unusually deep, with terraced walls leading down some 3km from its rim to its floor. At the centre of the crater is a central peak, and a system of bright rays - the remnant of the ancient impact that created the crater - stretch out across the lunar surface in all directions.