What is "calippus"

Calippus is a small lunar crater that is located on the eastern edge of the rugged Montes Caucasus mountain range in the northern part of the Moon. It lies to the southwest of the crater remnant Alexander, to the northwest of the Mare Serenitatis.

The outer rim of Calippus has an irregular appearance, with outward bulges to the northeast and particularly to the west where there is an interior shelf of slumped material. The exterior has a slight rampart that is surrounded by the rugged terrain of the mountain range. Within the sharp-sided interior walls is a rough and irregular interior floor.

To the southeast of this crater, on the edge of the Mare Serenitatis, is an arcing rille designated Rima Calippus. This cleft follows a path to the northeast for a length of about 40 kilometers.

Calippus may refer to:

• Calippus of Syracuse (died 352/51 BC), an Athenian student of Plato and tyrant of Syracuse
• Calippus of Cyzicus (c. 370–300 BC), a Greek astronomer and mathematician
• Calippus of Athens (fl. 279 BC), an Athenian commander in the Battle of Thermopylae (279 BC)
• Calippus (crater), a small lunar crater
• Calippus (genus), an extinct relation of the modern horse