CharacteristicsMare Crisium is in diameter, and in area. It has a very flat floor, with a ring of wrinkle ridges (''dorsa'') toward its outer boundaries. These are Dorsa Tetyaev, Dorsum Oppel, Dorsum Termier, and Dorsa Harker. The cape-like feature protruding into the southeast of the mare is Promontorium Agarum. On the western rim of the mare is the Palimpsest (geology), palimpsest Yerkes (crater), Yerkes, and Lick (crater), Lick to the southeast is similar. The Impact crater, crater Picard (crater), Picard is located just to the east of Yerkes, and northwest of Picard are the craters Peirce (crater), Peirce and Swift (lunar crater), Swift. The ray system of the crater Proclus (crater), Proclus overlie the northwestern mare. Mare Anguis can be seen northeast of Mare Crisium. A mass concentration (astronomy), mass concentration (mascon), or gravitational high, was identified in the center of Mare Crisium from Doppler tracking of the five Lunar Orbiter program, Lunar Orbiter spacecraft in 1968. The mascon was confirmed and mapped at higher resolution with later orbiters such as Lunar Prospector and Gravity Recovery and Interior Laboratory, GRAIL.
NamesLike most of the other maria on the Moon, Mare Crisium was named by Giovanni Riccioli, whose 1651 nomenclature system has become standardized.Ewen A. Whitaker, ''Mapping and Naming the Moon'' (Cambridge University Press, 1999), p.61. By the 17th century, Mare Crisium had acquired the name 'Caspian Sea', being labelled as such by Thomas Harriot, Pierre Gassendi and Michael Van Langren. Ewen A. Whitaker speculates that it received this name because it occupies roughly the same position on the Moon's face as does the Caspian Sea on Earth, with respect to T and O map, maps of Europe, North Africa and the Middle East.Ewen A. Whitaker, ''Mapping and Naming the Moon'' (Cambridge University Press, 1999), p.7. The English astronomer William Gilbert (astronomer), William Gilbert's map of ''c''.1600 calls it 'Brittania' after Great Britain, Britain.
Observation and explorationMare Crisium is just visible from Earth with the naked eye as a small dark spot on the edge of the Moon's face. It is the site of the crash-landing of Soviet Luna 15 probe in 1969. A soil sample from Mare Crisium was successfully brought to Earth on 22 August 1976 by the Soviet lunar mission Luna 24.