Mare Cognitum (Latin ''cognitum'', the "Sea that has Become Known") is a

lunar mare The lunar maria ( ; mare ) are large, dark, basaltic plains on Earth's Moon, formed by lava flowing into ancient impact basins. They are less reflective than the "highlands" as a result of their iron-rich composition, and hence appear dark to ...

located in a basin or large

crater A crater is a landform consisting of a hole or depression (geology), depression on a planetary surface, usually caused either by an object hitting the surface, or by geological activity on the planet. A crater has classically been described ...

which sits in the second ring of

Oceanus Procellarum Oceanus Procellarum ( ; from ) is a vast lunar mare on the western edge of the near side of the Moon. It is the only one of the lunar maria to be called an "Oceanus" (ocean), due to its size: Oceanus Procellarum is the largest of the maria ("s ...

. To the northwest of the mare is the Montes Riphaeus mountain range, part of the rim of the buried crater or basin containing the mare. Previously unnamed, the mare received its name in 1964 in reference to its selection as the target for the successful

impact probe Uncrewed spacecraft or robotic spacecraft are spacecraft without people on board. Uncrewed spacecraft may have varying levels of autonomy from human input, such as remote control, or remote guidance. They may also be autonomous, in which they ...

Ranger 7 Ranger 7 was the first NASA space probe to successfully transmit close-up images of the lunar surface back to Earth. It was also the first completely successful flight of the Ranger program. Launched on July 28, 1964, Ranger 7 was designed to a ...

, the first American spacecraft to return closeup images of the

Moon's surface Selenography is the study of the surface and physical features of the Moon (also known as geography of the Moon, or selenodesy). Like geography and areography, selenography is a subdiscipline within the field of planetary science. Historically, ...

Origin

The basin material is of the

Pre-Nectarian The pre-Nectarian period of the lunar geologic timescale runs from 4.533 billion years ago (the time of the initial formation of the Moon) to 3.920 billion years ago, when the Nectaris Basin was formed by a large impact. It is followed by the Necta ...

epoch In chronology and periodization, an epoch or reference epoch is an instant in time chosen as the origin of a particular calendar era. The "epoch" serves as a reference point from which time is measured. The moment of epoch is usually decided b ...

, while most of the

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

ic mare material is of the

Upper Imbrian The Imbrian is a lunar geologic period divided into two epochs, the Early and Late. Early Imbrian In the lunar geologic timescale, the Early Imbrian epoch occurred from 3,850 million years ago to about 3,800 million years ago. It overlaps the en ...

epoch.

Exploration

The

lunar probe impacted Mare Cognitum at the conclusion of its picture-taking mission.

Surveyor 3 Surveyor 3 is the third lander of the American uncrewed Surveyor program sent to explore the surface of the Moon in 1967 and the second to successfully land. It was the first mission to carry a surface-soil sampling-scoop. Surveyor 3 was vis ...

and

Apollo 12 Apollo 12 (November 14–24, 1969) was the sixth crewed flight in the United States Apollo program and the second to land on the Moon. It was launched on November 14, 1969, by NASA from the Kennedy Space Center in Florida. Commander Charles ...

landed near its northern shore. The outcrop of the

Fra Mauro formation The Fra Mauro formation (or Fra Mauro Highlands) is a Geology of the Moon, formation on the near side of the Moon, near side of Moon, Earth's Moon that served as the landing site for the American Apollo 14 mission in 1971. It is named after th ...

, where

Apollo 14 Apollo 14 (January 31February 9, 1971) was the eighth crewed mission in the United States Apollo program, the third to Moon landing, land on the Moon, and the first to land in the Geology of the Moon#Highlands, lunar highlands. It was the las ...

landed, is also located near Mare Cognitum.

Statio Cognitum

On November 19, 1969, astronauts

Pete Conrad Charles "Pete" Conrad Jr. (June 2, 1930 – July 8, 1999) was an American NASA astronaut, aeronautical engineer, naval officer, aviator, and test pilot who commanded the Apollo 12 mission, on which he became the third person to walk on t ...

and

Alan Bean Alan LaVern Bean (March 15, 1932 – May 26, 2018) was an American naval officer and aviator, aeronautical engineer, test pilot, NASA astronaut and painter. He was selected to become an astronaut by NASA in 1963 as part of Astronaut Grou ...

landed

Lunar Module The Apollo Lunar Module (LM ), originally designated the Lunar Excursion Module (LEM), was the lunar lander spacecraft that was flown between lunar orbit and the Moon's surface during the United States' Apollo program. It was the first crewed s ...

within walking distance of

, which had been on the Moon since 1967. Named "Statio Cognitum" the site's closeness to its intended target demonstrated

NASA The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the federal government of the United States, US federal government responsible for the United States ...

's capability of precise lunar landings. The location also provided a relatively smooth Mare surface and a proximity to the lunar equator, thus ensuring relative ease of access from the standpoint of fuel consumption. Geologically, the astronauts noted the amount of glass contained in the

regolith Regolith () is a blanket of unconsolidated, loose, heterogeneous superficial deposits covering solid rock. It includes dust, broken rocks, and other related materials and is present on Earth, the Moon, Mars, some asteroids, and other terrestria ...

and present at the bottoms of shallow craters at the site, as well as lighter-colored regolith material that geologists later determined to be

ejecta Ejecta (; ) are particles ejected from an area. In volcanology, in particular, the term refers to particles including pyroclastic rock, pyroclastic materials (tephra) that came out of a explosive eruption, volcanic explosion and magma eruption v ...

from Copernicus crater. The Copernicus ejecta sampled suggested that the Copernicus impact occurred about 800 million years ago, but geologists believe the results of this analysis are inconclusive. The Apollo 12 astronauts also noted the existence of small, shallow elongated depressions ("trenches" or "grooves") similar to those the

Apollo 11 Apollo 11 was a spaceflight conducted from July 16 to 24, 1969, by the United States and launched by NASA. It marked the first time that humans Moon landing, landed on the Moon. Commander Neil Armstrong and Lunar Module pilot Buzz Aldrin l ...

astronauts observed at

Tranquility Base Tranquility Base () is the site on the Moon where, in July 1969, humans landed and walked on a celestial body other than Earth for the first time. On July 20, 1969, Apollo 11 crewmembers Neil Armstrong and Buzz Aldrin landed their Apollo Lunar Mo ...

in the

Sea of Tranquility Mare Tranquillitatis (Latin for Sea of Tranquillity or Sea of Tranquility) is a lunar mare that sits within the Tranquillitatis basin on the Moon. It contains Tranquility Base, the first location on another celestial body to be visited by hu ...

; Shoemaker et al. preliminarily concluded in 1970 that these features reflected the direction and location of fractures in the underlying bedrock, into which fine-grained material settled, thereby creating the grooves. Overall, Statio Cognitum and the surrounding area appears to have a slightly more red coloration from lunar orbit than Tranquility Base (which geologists later found to be the result of less

titanium Titanium is a chemical element; it has symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion in ...

in the Apollo 12 rocks) and to have fewer craters overall than Tranquility Base; because of this, geologists suspected the site chosen for Apollo 12 contained younger rocks than those of the Apollo 11 site, and this was confirmed by the samples returned by Apollo 12. These samples consisted of more

s and fewer

breccia Breccia ( , ; ) is a rock composed of large angular broken fragments of minerals or Rock (geology), rocks cementation (geology), cemented together by a fine-grained matrix (geology), matrix. The word has its origins in the Italian language ...

s than the Apollo 11 samples and the basalts are about 500 million years younger than those from Tranquility base, the latter of which geologists estimate to be about 3.6 to 3.8 billion years old. The differing ages of the basalts collected on Apollo 11 and Apollo 12 demonstrate that the volcanic activity that formed the

did not occur all at once across the lunar surface, but rather took place at different times at different locations.

References

{{Authority control Cognitum Apollo 12 Apollo 14 Cognitum

Origin

Exploration

Statio Cognitum

See also

References