The Cayley Formation is a discontinuous unit of plains-forming material on the Moon. It was first recognized in the central near side of the Moon in 1965, by the Astrogeology group of the United States Geological Survey . It was previously mapped as part of the Fra Mauro formation . During the Apollo era, the formation was mapped in many other parts of the Moon including the far side (e.g., Mendeleev basin .)
25-596: The description of the formation from the 1967 edition of the Geologic Map of Julius Caesar Quadrangle (LAC-60) of the Moon follows: The formation was interpreted as: In the Cayley Formation near Cayley crater, the formation overlies Imbrium sculpture but is embayed by mare material and has a higher crater density than nearby maria. Thus, the Cayley Formation predates the mare but postdates sculpturing by
50-591: A map of the Moon that names Mare Imbrium "Regio Magna Orientalis" (the Large Eastern Region). Michael van Langren 's 1645 map named it "Mare Austriacum" (the Austrian Sea). Mare Imbrium is visible to the naked eye from Earth. In the traditional ' Man in the Moon ' image seen on the Moon in Western folklore, Mare Imbrium forms the man's right eye. On 17 November 1970 at 03:47 Universal Time,
75-476: A proto-planet from the asteroid belt collided with the Moon during the Late Heavy Bombardment . The impact is dated to approximately 3922 ± 12 million years ago, based on radiometric dating techniques. Ejecta from the impact covers large areas of the near side of the Moon. With a diameter of 1145 km, Mare Imbrium is second only to Oceanus Procellarum in size among the maria, and it
100-467: A storage repository of both biological and computer viruses, and in his short story " The Sentinel " (in which Wilson, the protagonist, mentions having climbed it). Pico is mentioned in the Jules Verne novel Around the Moon as the three main characters observe it from their spacecraft. Two of the travelers, Nichol and Ardan, suggest christening the nearby unnamed peak Barbicane, in honor of
125-456: Is a very reflective and bright object. Due to its isolated location on the lunar mare , this peak can form prominent shadows when illuminated by oblique sunlight. It is also known as a location of Transient Lunar Anomalies . A smaller peak to the southeast of Mons Pico is sometimes called Mons Pico β (Beta). This region of the mare contains a number of wrinkle ridges . By convention these features are identified on lunar maps by placing
150-695: Is compositionally distinct from the Apollo and Luna landing sites. Mons Pico Mons Pico is a solitary lunar mountain that lies in the northern part of the Mare Imbrium basin, to the south of the dark-floored crater Plato and on the southern rim of a ghost crater . This peak forms part of the surviving inner ring of the Imbrium basin, continuing to the northwest and with the Montes Teneriffe and Montes Recti ranges, and probably to
175-550: Is submerged under the mare's basalt, resulting in only isolated peaks remaining in some areas, such as Mons Pico and Mons La Hire . Numerous estimates of the depth of the mare material have been made using various methods. These include analyses of gravity, seismic, and radar data; studies of craters partially filled with basalt and those that have completely penetrated the mare; and comparisons of lunar basins filled with mare deposits to unfilled basins. These studies have yielded depth estimates ranging from 2 km to 5 km in
200-620: Is the largest mare associated with an impact basin. The Imbrium Basin is surrounded by three concentric rings of mountains, uplifted by the colossal impact event that excavated it. The outermost ring of mountains has a diameter of 1300 km and is divided into several different ranges; the Montes Carpatus to the south, the Montes Apenninus to the southeast, and the Montes Caucasus to the east. At their highest,
225-542: The Apennine Mountains . Commander David Scott and Lunar Module Pilot James Irwin spent three days on the surface of the Moon, including 18½ hours outside the spacecraft on lunar extra-vehicular activity . Command Module Pilot Alfred Worden remained in orbit and acquired hundreds of high-resolution photographs of Mare Imbrium (and other regions of the Moon) as well as other types of scientific data. The crew on
250-644: The " Sea of Showers " or " Sea of Rains ") is a vast lava plain within the Imbrium Basin on the Moon and is one of the larger craters in the Solar System . The Imbrium Basin formed from the collision of a proto-planet during the Late Heavy Bombardment . Basaltic lava later flooded the giant crater to form the flat volcanic plain seen today. The basin's age has been estimated using uranium–lead dating methods to approximately 3.9 billion years ago, and
275-574: The Imbrian event. One of the main objectives of the Apollo 16 mission to the Moon in 1972 was to obtain samples of the Cayley Formation, and also the adjacent Descartes Formation. Most scientists predicted that volcanic rocks would be obtained from the Cayley Formation, but the astronauts ( Charles Duke and John Young ) found almost nothing but breccias . The Cayley Formation was heavily sampled at Flag , Spook , and North Ray craters, as well as at
SECTION 10
#1732797793104300-681: The Lunar Module (LM) Orion and geology stations southwest of the LM. The lack of volcanic rocks returned from the Cayley forced a reinterpretation of its origin. The Cayley was reinterpreted to be a fluidized ejecta deposit resulting from the formation of the Imbrium basin or of the Orientale basin , which occurred after the Imbrium basin-forming event. Imbrium sculpture Mare Imbrium / ˈ ɪ m b r i ə m / ( Latin imbrium ,
325-417: The Moon's entire lithosphere . At the region of the Moon's surface exactly opposite Imbrium Basin, there is a region of chaotic terrain (the crater Van de Graaff ) which is thought to have been formed when the seismic waves of the impact were focused there after travelling through the Moon's interior. Mare Imbrium is about 750 miles (1,210 km) wide. A mass concentration (mascon), or gravitational high,
350-422: The Moon's surface by large projectiles blasted out of the basin at low angles, causing them to skim across the lunar surface ploughing out these features. The sculpture pattern was first identified by Grove Karl Gilbert in 1893. Furthermore, a Moon-wide pattern of faults which run both radial to and concentric to the Imbrium basin were thought to have been formed by the Imbrium impact; the event literally shattered
375-507: The Soviet spacecraft Luna 17 made a soft landing in the mare, at latitude 38.28 N, and longitude 35.00 W. Luna 17 carried Lunokhod 1 , the first robotic rover to be deployed on the Moon or any extraterrestrial body. Lunokhod 1, a remote-controlled rover, was successfully deployed and undertook a mission lasting several months. In 1971, the crewed Apollo 15 mission landed in the southeastern region of Mare Imbrium, between Hadley Rille and
400-504: The Yutu rover 7 hours and 24 minutes later. Chang'e 3 mission attempted to perform the first direct measurement of the structure and depth of the lunar soil down to a depth of 30 m (98 ft), and investigate the lunar crust structure down to several hundred meters deep. The rover's ground penetrating radar found evidence of at least nine distinct rock layers , indicating that the area had surprisingly complex geological processes and
425-457: The central part of the mare. It is thought that the original crater left by the Imbrium impact was as much as 100 km deep, but that the floor of the basin bounced back upwards immediately afterwards. Surrounding the Imbrium Basin is a region blanketed by ejecta from the impact, extending roughly 800 km outward. Also encircling the basin is a pattern of radial grooves called the "Imbrium Sculpture", which have been interpreted as furrows cut in
450-407: The diameter of the impactor has been estimated to be 250 ± 25 km. The Moon's maria (plural of mare ) have fewer features than other areas of the Moon because molten lava pooled in the craters and formed a relatively smooth surface. Mare Imbrium is not as flat as it would have originally been when it first formed as a result of later events that have altered its surface. Mare Imbrium formed when
475-510: The letter on the side of the crater midpoint that is closest to Mons Pico. Strange objects appear near Pico in the 1957 science fiction novel Blast Off at Woomera by Hugh Walters ; their fate is further expanded upon in the sequels The Domes of Pico and Operation Columbus . Pico is the site of a climactic space battle in Arthur C. Clarke 's novel Earthlight . It is also mentioned in passing in his novel 3001: The Final Odyssey as
500-503: The mare may be "The Shrine of Hecate "; Plutarch records that the Ancient Greeks gave this name to the largest of the "hollows and deeps" on the Moon, believing it to be the place where the souls of the deceased were tormented. Ewen A. Whitaker argues that this likely refers to Mare Imbrium, "the largest regular-shaped dark area unbroken by bright patches" that can be seen with the naked eye. Around 1600, William Gilbert made
525-541: The outer ring of mountains rise more than 5 km above the surface of Mare Imbrium. The ring mountains are not as well developed to the north and west, and it appears they were simply not raised as high in these regions by the Imbrium impact. The middle ring of mountains forms the Montes Alpes and Montes Archimedes . The innermost ring, with a diameter of 650 km, is defined by Montes Recti , Montes Teneriffe , and possibly Montes Spitzbergen . Much of this ring
SECTION 20
#1732797793104550-510: The rille wall. On 17 March 2013, an object hit the lunar surface in Mare Imbrium and exploded in a flash of apparent magnitude 4. The resulting crater was 18 meters wide. This was the brightest impact recorded since NASA's lunar impact team began monitoring in 2005. Chang'e 3 landed on 14 December 2013 on Mare Imbrium, about 40 km south of the 6 km diameter Laplace F crater, at 44.1260°N 19.5014°W. The lander deployed
575-548: The southeast with the Montes Spitzbergen . This mountain feature is thought to have been named by Johann Hieronymus Schröter for Pico del Teide on Tenerife . Mons Pico forms an elongated feature with a length of 25 kilometers (oriented northwest-southeast) and a width of 15 km. The peak rises to a height of 2.4 km, comparable to the maximum altitude of the Montes Teneriffe. The mountain itself
600-429: The surface explored the area using the first lunar rover and returned to Earth with 77 kilograms (170 lb) of lunar surface material. Samples were collected from Mons Hadley Delta , believed to be a fault block of pre-Imbrian ( Nectarian or Pre-Nectarian ) lunar crust, including the " Genesis Rock ." This was also the only Apollo mission to visit a lunar rille, and to observe outcrops of lunar bedrock visible in
625-451: Was identified in the center of Mare Imbrium from Doppler tracking of the five Lunar Orbiter spacecraft in 1968. The Imbrium mascon is the largest on the Moon. It was confirmed and mapped at higher resolution with later orbiters such as Lunar Prospector and GRAIL . Like most of the other maria on the Moon, Mare Imbrium was named by Giovanni Riccioli , whose 1651 nomenclature system has become standardized. The earliest known name for
#103896