Mare Crisium (Latin ''crisium'', the "Sea of Crises") is a

lunar mare The lunar maria (; singular: mare ) are large, dark, basaltic plains on Earth's Moon, formed by ancient asteroid impacts on the far side on the Moon that triggered volcanic activity on the opposite (near) side. They were dubbed , Latin for 'seas' ...

located in the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

's Crisium basin, just northeast of

Mare Tranquillitatis Mare Tranquillitatis (Latin ''tranquillitātis'', the Sea of Tranquillity or Sea of Tranquility; see spelling differences) is a lunar mare that sits within the Tranquillitatis basin on the Moon. It is the first location on another world to be ...

. The basin is of the Pre-Imbrian period, 4.55 to 3.85 billion years ago.

Characteristics

Mare Crisium is in diameter, and in area. It has a very flat floor, with a ring of

wrinkle ridge A wrinkle ridge is a type of feature commonly found on lunar maria, or basalt plains. These features are low, sinuous ridges formed on the mare surface that can extend for up to several hundred kilometers. Wrinkle ridges are tectonic features c ...

s (''dorsa'') toward its outer boundaries. These are Dorsa Tetyaev, Dorsum Oppel, Dorsum Termier, and

Dorsa Harker Dorsa Harker is a wrinkle ridge at in Mare Crisium on the Moon. It is 213 km long and was named after Alfred Harker, an English English usually refers to: * English language * English people English may also refer to: ...

. The cape-like feature protruding into the southeast of the mare is Promontorium Agarum. On the western rim of the mare is the palimpsest Yerkes, and Lick to the southeast is similar. The

crater Crater may refer to: Landforms * Impact crater, a depression caused by two celestial bodies impacting each other, such as a meteorite hitting a planet * Explosion crater, a hole formed in the ground produced by an explosion near or below the surf ...

Picard is located just to the east of Yerkes, and northwest of Picard are the craters Peirce and

Swift Swift or SWIFT most commonly refers to: * SWIFT, an international organization facilitating transactions between banks ** SWIFT code * Swift (programming language) * Swift (bird), a family of birds It may also refer to: Organizations * SWIFT, ...

. The

ray system A ray system comprises radial streaks of fine ''ejecta'' thrown out during the formation of an impact crater, looking somewhat like many thin spokes coming from the hub of a wheel. The rays may extend for lengths up to several times the diameter ...

of the crater

Proclus Proclus Lycius (; 8 February 412 – 17 April 485), called Proclus the Successor ( grc-gre, Πρόκλος ὁ Διάδοχος, ''Próklos ho Diádokhos''), was a Greek Neoplatonist philosopher, one of the last major classical philosophe ...

overlie the northwestern mare. Mare Anguis can be seen northeast of Mare Crisium. A mass concentration (mascon), or gravitational high, was identified in the center of Mare Crisium from Doppler tracking of the five Lunar Orbiter spacecraft in 1968. The mascon was confirmed and mapped at higher resolution with later orbiters such as

Lunar Prospector ''Lunar Prospector'' was the third mission selected by NASA for full development and construction as part of the Discovery Program. At a cost of $62.8 million, the 19-month mission was designed for a low polar orbit investigation of the Moon ...

and

GRAIL The Gravity Recovery and Interior Laboratory (GRAIL) was an American lunar science mission in NASA's Discovery Program which used high-quality gravitational field mapping of the Moon to determine its interior structure. The two small spacecraf ...

. File:Crisium basin topo.jpg, Topographic map File:Crisium basin GRAIL gravity.jpg, Gravity map based on

Names

Like 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 Thomas Harriot (; – 2 July 1621), also spelled Harriott, Hariot or Heriot, was an English astronomer, mathematician, ethnographer and translator to whom the theory of refraction is attributed. Thomas Harriot was also recognized for his con ...

Pierre Gassendi Pierre Gassendi (; also Pierre Gassend, Petrus Gassendi; 22 January 1592 – 24 October 1655) was a French philosopher, Catholic priest, astronomer, and mathematician. While he held a church position in south-east France, he also spent much t ...

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 The Caspian Sea is the world's largest inland body of water, often described as the world's largest lake or a full-fledged sea. An endorheic basin, it lies between Europe and Asia; east of the Caucasus, west of the broad steppe of Central A ...

on Earth, with respect to 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's map of ''c''.1600 calls it 'Brittania' after Britain.

Observation and exploration

Mare 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.

Views

File:Location of Mare Crisium.jpg, Location of Mare Crisium, as seen from the Earth File:Mare Crisium AS17-M-0913-0919-0924.jpg, These are three views of northern Mare Crisium on the Moon, taken by the mapping camera of the

Apollo 17 Apollo 17 (December 7–19, 1972) was the final mission of NASA's Apollo program, the most recent time humans have set foot on the Moon or traveled beyond low Earth orbit. Commander Gene Cernan and Lunar Module Pilot Harrison Schmitt walke ...

mission in 1972, facing north-northeast from an average altitude of 118 km on Revolution 27 of the mission. At the right is the east margin of Mare Crisium, with the north tip of Promontorium Agarum visible in the foreground, and Mare Anguis near the central horizon. The crater Eimmart is visible in both the right and central photos as a bright patch (near the top in each). The center photo shows an obvious lack of large craters in the mare indicating a relatively young age of the basalt, and the crater Eimmart C is visible as a ring at the edge of the mare near the top center. The left photo shows the western margin of the mare, with the crater Peirce (larger) and

(smaller) in the mare, and the large crater

Cleomedes Cleomedes ( el, Κλεομήδης) was a Greek astronomer who is known chiefly for his book ''On the Circular Motions of the Celestial Bodies'' (Κυκλικὴ θεωρία μετεώρων), also known as ''The Heavens'' ( la, Caelestia). Pl ...

near the central horizon. The rays of the crater

(further to the west, not shown) are prominent in the mare. These photos were taken within minutes of each other. The sun elevation drops from 60 degrees at right to 46 degrees at left as the Command Module ''America'' orbited the Moon. Image:Mare Crisium AS11-43-6484.jpg, Low-altitude view of southern Mare Crisium from

Apollo 11 Apollo 11 (July 16–24, 1969) was the American spaceflight that first landed humans on the Moon. Commander Neil Armstrong and lunar module pilot Buzz Aldrin landed the Apollo Lunar Module ''Eagle'' on July 20, 1969, at 20:17 UTC, ...

, facing northwest and showing the crater Shapley near center at the edge of the mare, and the distal wall of the crater Greaves near the horizon.

References

External links

High resolution lunar overflight video
by Seán Doran, based on LRO data, that passes near Mare Crisium (se
album
for more); a longer version that starts over the western margin of

Mare Fecunditatis Mare Fecunditatis (Latin ''fēcunditātis'', the "Sea of Fecundity" or "Sea of Fertility") is a lunar mare in the eastern half of the visible Moon. The mare has a maximum diameter of 840 km. __NOTOC__ Description The Fecunditatis basin form ...