Mare Serenitatis

Mare Serenitatis is a large lunar mare, or basalt-covered plain, located east of Mare Imbrium on the Moon's near side. Its name means “Sea of Serenity” in Latin, following the naming system established by the Italian astronomer Giovanni Riccioli in 1651. The feature spans approximately 674 kilometres across and occupies most of the Serenitatis impact basin. Unlike an earthly sea, it contains no liquid water; its relatively dark appearance results primarily from extensive basaltic lava deposits that flooded the basin after its formation. The mare is surrounded by and connected to several other major lunar regions. It joins Mare Tranquillitatis toward the southeast and borders Mare Vaporum to the southwest. To the northeast, basalt from the mare extends into Lacus Somniorum. The crater Posidonius is a prominent feature on the northeastern rim, while the Montes Haemus range forms the clearest surviving part of the basin's western ring. The eastern boundary includes the Montes Taurus region and the Taurus–Littrow valley, an area of considerable importance in the history of lunar exploration. Geologically, Mare Serenitatis lies within the Serenitatis basin, whose main impact structure dates to the Nectarian epoch. The surrounding terrain is generally associated with the Lower Imbrian epoch, while much of the mare's basalt is assigned to the Upper Imbrian epoch. The basin is also a mascon, or mass concentration: an area where denser material produces an anomalous gravitational signal. Doppler tracking of the five Lunar Orbiter spacecraft identified the central gravitational high in 1968. Later missions, including Lunar Prospector and the Gravity Recovery and Interior Laboratory spacecraft, refined the mapping and understanding of this subsurface structure. The region has been visited or targeted by several lunar missions. The Soviet Luna 21 spacecraft landed in Le Monnier crater near the mare's eastern border. NASA's Apollo 17 mission landed in the Taurus–Littrow valley in December 1972 and collected samples and observations from the surrounding Montes Taurus area. SpaceIL's Beresheet lander was intended to land in Mare Serenitatis, but the spacecraft crashed during its descent on 11 April 2019; its final impact site was reported near the mare's central area. Mare Serenitatis has also had a durable cultural presence. Its broad dark region contributes to the traditional “Man in the Moon” pattern, where it is sometimes interpreted as one of the figure's eyes. The feature appears in or is mentioned by works of science fiction, including Arthur C. Clarke's “The Sentinel,” John Wyndham's “The Last Lunarians,” and Robert A. Heinlein's The Moon Is a Harsh Mistress. It has also appeared in music artwork, video games, and the Sailor Moon fictional setting. In this dossier, the subject is treated as the canonical astronomical entity rather than as a commercial consumer brand.

Mare Serenitatis is the visible basaltic plain occupying much of the Serenitatis basin on the Moon's near side. The basin formed through a major impact during the Nectarian epoch. Subsequent volcanic activity filled much of the depression with mare basalt, producing the broad, relatively dark surface recognized in telescopic images. The surrounding terrain is generally attributed to the Lower Imbrian epoch, whereas the mare deposits themselves are associated with the Upper Imbrian epoch. Basalt also spilled northeastward into Lacus Somniorum, demonstrating that the lava-filled area extended beyond the principal basin floor. The feature is approximately 674 kilometres in diameter. Its boundaries are defined by neighbouring maria, basin rims, mountain systems, and large craters rather than by a sharply continuous circular wall. Mare Tranquillitatis lies to the southeast and Mare Vaporum to the southwest. The Montes Haemus range is the most distinct remnant of the western basin ring, while the prominent crater Posidonius marks the northeastern rim. The Taurus Mountains and Taurus–Littrow valley lie along the eastern side and later became important destinations for robotic and crewed exploration. Mare Serenitatis is a lunar mascon. The term refers to a regional gravitational anomaly caused by an unusually dense concentration of material beneath a large impact basin. In 1968, Doppler observations from the five Lunar Orbiter spacecraft showed that the central area contained a gravitational high. This result helped establish that some lunar basins possess substantial subsurface mass concentrations rather than being simple, uniformly filled depressions. Lunar Prospector and the GRAIL mission later supplied higher-resolution gravitational and geological information, improving the map of the mascon and the structure beneath the mare. The name has a long history of competing lunar cartographic traditions. Around 1600, William Gilbert placed the region within Regio Magna Occidentalis, meaning the “Large Western Region.” Pierre Gassendi incorporated it into a figure he called Homuncio, or “little man,” and also used the name Thersite. Michael van Langren labelled it Mare Eugenianum in a 1645 map, honouring Isabella Clara Eugenia, queen of the Spanish Netherlands. Johannes Hevelius included the region within Pontus Euxinus, using the classical name for the Black Sea. Giovanni Riccioli's 1651 nomenclature assigned the Latin name Mare Serenitatis, which later became the standard designation. Exploration has given the mare significance beyond lunar cartography. Luna 21 landed in Le Monnier crater near its eastern border. Apollo 17 touched down in the Taurus–Littrow valley in December 1972, conducting the final crewed lunar surface mission to date and examining the geological setting near the mare. The mission's photographs and samples made the area one of the best-documented regions of the Moon. SpaceIL's Beresheet mission later selected Mare Serenitatis as its intended landing region, but the lander crashed during descent on 11 April 2019. The landscape has also been used repeatedly in cultural and fictional contexts. Its dark shape contributes to interpretations of the Man in the Moon and it is referenced in Arthur C. Clarke's 1951 story “The Sentinel,” John Wyndham's 1933 story “The Last Lunarians,” and Robert A. Heinlein's 1966 novel The Moon Is a Harsh Mistress. The region appears in the setting of Sailor Moon, on the 1982 Apollo - Atmospheres and Soundtracks album artwork, and as the name of a playable frigate in the game Infinite Lagrange. These appearances reflect the mare's status as a recognizable lunar landmark rather than evidence of commercial ownership or brand activity.

• 2019

  Beresheet landing attempt ends in a crash

  [1]Mare Serenitatisen.wikipedia.org

  SpaceIL's Beresheet lander was intended to reach Mare Serenitatis but crashed during descent on 11 April 2019.

• 1972

  Apollo 17 explores the Taurus–Littrow region

  [1]Mare Serenitatisen.wikipedia.org

  Apollo 17 landed near the eastern boundary of Mare Serenitatis and explored the Taurus–Littrow valley.

• 1968

  Central gravitational mascon detected

  [1]Mare Serenitatisen.wikipedia.org

  Doppler tracking of the Lunar Orbiter spacecraft identified a mass concentration beneath the central mare.

• 1651

  Riccioli establishes the standard name Mare Serenitatis

  [1]Mare Serenitatisen.wikipedia.org

  Giovanni Riccioli's lunar nomenclature assigned the Latin name Mare Serenitatis, which became the accepted designation.

• 1647

  Hevelius places it within Pontus Euxinus

  [1]Mare Serenitatisen.wikipedia.org

  Johannes Hevelius included the region within his larger designation Pontus Euxinus.

• 1645

  Van Langren labels the area Mare Eugenianum

  [1]Mare Serenitatisen.wikipedia.org

  Michael van Langren used the name Mare Eugenianum in a lunar map, honouring Isabella Clara Eugenia.

• 1600

  William Gilbert includes the region in Regio Magna Occidentalis

  [1]Mare Serenitatisen.wikipedia.org

  In an early lunar map, William Gilbert treated the area as part of Regio Magna Occidentalis, or the Large Western Region.

A scientifically significant lunar geological feature and historically prominent exploration location, not a conventional commercial brand.

• 1651

  Adoption of the Mare Serenitatis designationOther

  Background

  Several early lunar cartographers used different names for the region before Riccioli's nomenclature became influential.

  Action taken

  Giovanni Riccioli named the feature Mare Serenitatis, meaning Sea of Serenity, in his lunar naming system.

  Aftermath

  The designation became the standard modern name for the lunar mare.

  Source

1. 1Mare Serenitatisen.wikipedia.org