Mare Tranquillitatis is a lunar mare that sits within the Tranquillitatis basin on the Moon. It is the first location on another world to be visited by humans.
Mare Nectaris is a small lunar mare or sea located south of Mare Tranquillitatis southwest of Mare Fecunditatis, on the near side of the moon. Montes Pyrenaeus borders the mare to the east and Sinus Asperitatis fuses to its northwestern edge. It is 84,000 square kilometers in size.
Thebit is a lunar impact crater located on the southeast shore of Mare Nubium. To the north-northwest is the crater Arzachel, and Purbach lies to the south-southwest. To the southwest is the flooded remnants of Thebit P, which is actually larger in diameter than Thebit itself.
Catharina is an ancient lunar impact crater located in the southern highlands. It was named after Saint Catherine of Alexandria. It lies in a rugged stretch of land between the Rupes Altai scarp to the west and Mare Nectaris in the east. To the west-northwest is the crater Tacitus, and the lava-flooded Beaumont lies to the east along the shore of Mare Nectaris. To the south-southeast is Polybius.
Aitken is a large lunar impact crater that lies on the far side of the Moon, named for Robert Grant Aitken, an American astronomer specializing in binary stellar systems. It is located to the southeast of the crater Heaviside, and north of the unusual formation Van de Graaff. Attached to the southwest rim is Vertregt. To the southeast is the smaller Bergstrand.
Cauchy is a small lunar impact crater on the eastern Mare Tranquillitatis. It was named after French mathematician Augustin-Louis Cauchy. It is circular and symmetric, with a small interior floor at the midpoint of the sloping inner walls. Due to the high albedo of this bowl-shaped formation, it is particularly prominent at full Moon.
Tacitus is a lunar impact crater located to the northwest of the crater Catharina, at the northern extension of the Rupes Altai ridge line. It was named after the 1st century Roman historian and writer Tacitus. Directly west is the crater Almanon, and to the northeast is Cyrillus. To the southeast of Tacitus is a long chain of craters named the Catena Abulfeda. This chain runs to the northwest from the eastern edge of the Rupes Altai, continuing for over 200 kilometers.
Buys-Ballot is an oddly-shaped lunar impact crater that is located on the far side of the Moon. It lies just to the northwest of the small lunar mare named Lacus Luxuriae, and southeast of the crater Freundlich. Other nearby craters of note are Anderson to the southwest and Dante to the northeast.
Vitello is a lunar impact crater that lies along the southern edge of the small Mare Humorum, in the southwest part of the Moon's near side. It was named after 13th century Polish theologian and physicist Vitello. It lies just to the east of the lava-flooded crater Lee. To the northeast along the edge of the lunar mare is the Rupes Kelvin, an irregular fault line.
Montes Cordillera is a mountain range on the Moon. This feature forms the outer wall of peaks that surround the Mare Orientale impact basin, the inner ring being formed by the Montes Rook. The center of the range is located at selenographic coordinates 17.5° S, 81.6° W, and the diameter is 574 km (357 mi).
Rupes Recta is a linear fault on the Moon, in the southeastern part of the Mare Nubium at 22.1°S 7.8°W. The name is Latin for straight cliff, although it is more commonly called the Straight Wall. This is the most well-known escarpment on the Moon, and is a popular target for amateur astronomers.
Rupes Altai is an escarpment in the lunar surface that is located in the southeastern quadrant of the Moon's near side. It is named for the Altai Mountains in Asia, and is the most prominent lunar escarpment. The selenographic coordinates of this feature are 24.3°S 22.6°E, and it has a length of about 427 km.
Rupes Cauchy is a 120 km-long escarpment at 9.0°N 37.0°E on the surface of the Moon. It faces southwest, and rises about 200–300 m. It is located in the northeastern portion of the Mare Tranquillitatis, and is named after the nearby crater Cauchy.
The Bach quadrangle encompasses the south polar part of Mercury poleward of latitude 65° S. It is named after the prominent crater Bach within the quadrangle, which is in turn named after Baroque composer Johann Sebastian Bach. The quadrangle is now called H-15.
The Discovery quadrangle lies within the heavily cratered part of Mercury in a region roughly antipodal to the 1550-km-wide Caloris Basin. Like the rest of the heavily cratered part of the planet, the quadrangle contains a spectrum of craters and basins ranging in size from those at the limit of resolution of the best photographs to those as much as 350 km across, and ranging in degree of freshness from pristine to severely degraded. Interspersed with the craters and basins both in space and time are plains deposits that are probably of several different origins. Because of its small size and very early segregation into core and crust, Mercury has seemingly been a dead planet for a long time—possibly longer than the Moon. Its geologic history, therefore, records with considerable clarity some of the earliest and most violent events that took place in the inner Solar System.
The Michelangelo quadrangle is in the southern hemisphere of the planet Mercury, where the imaged part is heavily cratered terrain that has been strongly influenced by the presence of multiring basins. At least four such basins, now nearly obliterated, have largely controlled the distribution of plains materials and structural trends in the map area. Many craters, interpreted to be of impact origin, display a spectrum of modification styles and degradation states. The interaction between basins, craters, and plains in this quadrangle provides important clues to geologic processes that have formed the morphology of the mercurian surface.
Rembrandt is a large impact crater on Mercury. With a diameter of 715 km it is the second-largest impact basin on the planet, after Caloris, and is one of the larger craters in the Solar System. It was discovered by MESSENGER during its second flyby of Mercury on October 6, 2008. The crater is 3.9 billion years old, and was created during the period of Late Heavy Bombardment. The density and size distribution of impact craters along Rembrandt's rim indicate that it is one of the youngest impact basins on Mercury.
Rousillon Rupes is a scarp on the surface of the Uranian moon Titania named after "Bertram, count of Rousillon" in William Shakespeare's comedy All's Well That Ends Well. The 402 km long feature is a normal fault situated near the equator and running perpendicular to it. The scarp cuts impact craters, which probably means that it was formed at a relatively late stage of moon's evolution, when the interior of Titania expanded and its ice crust cracked as a result. Rousillon Rupes has only few crater superimposed on it, which also implies its relatively young age. The scarp was first imaged by Voyager 2 spacecraft in January 1986.
Volcanism on the Moon is represented by the presence of volcanoes, pyroclastic deposits and vast lava plains on the lunar surface. The volcanoes are typically in the form of small domes and cones that form large volcanic complexes and isolated edifices. Calderas, large-scale collapse features generally formed late in a volcanic eruptive episode, are exceptionally rare on the Moon. Lunar pyroclastic deposits are the result of lava fountain eruptions from volatile-laden basaltic magmas rapidly ascending from deep mantle sources and erupting as a spray of magma, forming tiny glass beads. However, pyroclastic deposits formed by less common non-basaltic explosive eruptions are also believed to exist on the Moon. Lunar lava plains cover large swaths of the Moon's surface and consist mainly of voluminous basaltic flows. They contain a number of volcanic features related to the cooling of lava, including lava tubes, rilles and wrinkle ridges.
