Appendix A Fundamentals of selenography This appendix details some quint-essentials of selenography, and serves as a basic reference for lunar surface features and a first-order map of the lunar geology (se­ lenology). Figures A.l and A.2 schematically show, in a simple cylindrical projec­ tion, the characteristic features of the Moon and relate the names to selenograph­ icallocation. A more detailed description of the quintessential maria, basins and craters, including their location, approximate size and geophysical characteristics is given in near-stenographical form in the extended tables. Most of the tabulated information is extracted and/ or derived from Spudis [1996]. Lunar maria Name and Location Description Mare Crisium Mascon mare near the east limb; low to very low (10-25° N, 50-70° E) titanium basalts, extruded around 3.4 Gyr ago Mare Fecunditatis Complex, shallow mare made up of low-, (5° N - 20° 5, 40-60° E) moderate-, and high-titanium basalts, extruded about 3.4 Gyr ago Mare Humorum Mascon mare on the southwestern near-side of (18-30° 5,31-48° W) the Moon, filled with moderately high-titanium basalts, 3.2-3.5 Gyr old Mare Imbrium Mascon mare on the near-side, deeply filled with (15-50° N, 40° W-5° E) low- and high-titanium basalts; age: from 3.3 to less than 2 Gyr old 232 Fundamentals of selenography Mare N ectaris Mascon mare on the central near-side; low­ (10-20° 5,30-40° E) titanium basalts covering very high titanium basalts; age: 3.8-3.5 Gyr Mare Nubium Complex, shallow mare; low- and high-titanium (10-30° 5,5-25° W) lava flows; age: 3.3-3.0 Gyr Mare Serenitatis Mascon mare; very high titanium lavas around (15-40° N, 5-20° E) the margins and centre of very low titanium lava; age: 3.8-3.3 Gyr Mare Smythii Mascon mare, very shallow; moderate-titanium (5° N-5° 5,80-95° E) lava; possibly extremely young (1-1.5 Gyr) Mare Tranquillitatis Complex, shallow, irregular mare; site of the first (0-20° N, 15-45° E) lunar landing; old (3.8 Gyr), with very high tita­ nium lavas Oceanus Procell arum Complex, shallow, irregular mare; largest on the (10° 5-60° N, 10-80° W) Moon; many compositions, with ages including the youngest lavas on the Moon (less than 1 Gyr old) Sinus Medii Small patch of mare near the exact centre of the (3° 5-5° N, 5° W-5° E) lunar near-side; site of the Surveyor 6 landing (1967) Lunar craters Name and Location Description Albategnius Large crater in the central highlands, sketched (11.2° 5,4.1 ° E; 136 km) by Galileo in 1610 Alphonsus Old crater with three dark, volcanic cinder cones (13.4° 5,2.8° W; 119 km) on its floor Archimedes Crater flooded by mare basalt, demonstrating (29.7° N, 4.0° W; 83 km) time span between Imbrium basin and its mare fill Aristarchus Very fresh crater excavating highland debris (23.7° N,47.4° W; 40 km) from beneath mare basalt cover Compton Small central-peak-plus-ring basin near lunar (56.0° N, 105.0° E; 160 km) north pole Cone Small, fresh crater excavating Fra Mauro brec­ (3S 5, 17S W; 370 m) cias that were sampled on the Apollo 14 mission, 1971 Copernicus Relatively young impact crater south of Mare (9.7° N, 20.0° W; 93 km) Imbrium; defines Copernican stratigraphic sys­ tem A Fundamentals of selenography 233 Descartes Old crater in central highlands, near the landing (11.7° S, 15.7° E; 48 krn) site of Apollo 16, 1972 Eratosthenes Unrayed crater near Mare Imbrium; defines Er­ (14S N, 11.3° W; 58 krn) atosthenian stratigraphic system Flamsteed P Old crater flooded by some of the youngest (1 (3.0° S, 44.0° W; 112 km) Gyr) lavas on the Moon; site of the Surveyor 1 landing in 1966 FraMauro Old crater covered by ejecta from the Imbrium (6.0° S, 17.0° W; 95 krn) impact basin; near the landing site of Apollo 14, 1971 Herigonius Small crater north of Mare Humorum, near some (13.3° S, 34.0° W; 15 krn) of the most spectacular sinuous rilles in the maria Hortensius Small crater, near which occur many small lunar (6.50° N, 28.0° W; 15 krn) shield volcanoes Kopff Unusual crater, long thought to be volcanic, in (17.4° S, 89.6° W; 42 krn) Orientale basin; may have been created by an impact into a semi-molten melt sheet Lamont Ridge ring system in Mare Tranquillitatis, (5.0° N, 23.2° E; 175 krn) formed over a two-ring basin Letronne Crater largely flooded by mare basalt in Oceanus (10.6° S, 42.4° W; 120 km) Procellarum Lichtenberg Rayed crater that is partly covered by a very (31.8° N, 67.7° W; 20 km) young mare lava flow, possibly less than 1 Gyr old Linne Very fresh, bright crater in Mare Serenitatis, re­ (27.7° N, 11.8° E; 2 km) ported before the space age to appear and disap­ pear Ritter Forms together with Sabine an unusual twin (2.0° N, 19.2° E; 29 krn) impact crater in Mare Tranquillitatis, similar in morphology to Kopff Sabine See Ritter (1.4° N, 20.1° E; 30 km) Shorty Small impact crater at the Apollo 17 landing site, (20.0° N, 31.0° E; 110 m) 1972; excavated dark mantle ash from beneath a layer of highland debris Sulpicius Gallus Crater near a large exposure of dark mantle de­ (19.6° N; 11.6° E; 12 krn) posits. Theophilus Large crater on the edge of Mare Nectaris. (11.4° S, 26.4° E; 100 krn) Tsiolkovsky Spectacular, mare-filled crater on the lunar far­ (20.4° S, 129.1 ° E; 180 km) side. 234 Fundamentals of selenography Tycho Fresh, prominent rayed crater on the near-side of (43.3° 5, 11.2° W; 85 km) the Moon; rays extend across entire hemisphere; central peak exposes deep-seated rocks Van de Graaff Double crater on the far-side; site of a major geo­ (27.0° 5, 172.0° E; 234km) chemical anomaly caused by its location just in­ side the rim of 50uth Pole Aitken basin Lunar basins Name and Location Description Crisium basin Nectarian-age multiring basin; ejecta possibly (17S N, 58S E; 740 km) sampled by the Luna 20 mission Humorum basin Nectarian-age basin south of Procellarum (24° 5, 39S W, 820 km) Imbrium basin Major large basin on the Moon; defines base of (33° N, 17° W, 1,150 km) Imbrian 5ystem; formed 3.84 Gyr ago; its ejecta was the sampling objective of the Apollo 14 and 15 missions Nectaris basin Defines base of Nectarian 5ystem; possibly sam­ (16° 5,34° E; 860 km) pled on the Apollo 16 mission in 1972; age: 3.92 Gyr Orientale basin Youngest large, multiring basin on the Moon, (20° 5, 95° W; 930km) formed sometime after 3.84 billion years ago; its interior and exterior deposits were used as a guide to interpret older, degraded basins Procellarum basin Alleged impact basin, supposedly the largest on (26° N, 15° W; 3,200 km) the Moon; Clementine laser altimetry data do not support its existence 5chrbdinger Type example of a two-ring basin, near the south (75.6° 5, 133.7° E; 320 km) pole of the Moon; formed after Imbrium basin but before Orientale basin 5erenitatis basin Nectarian-age multiring basin, sampled and ex­ (27° N, 19° E; 900 km) plored by Apollo 17 mission in 1972; age: 3.87 Gyr 50uth Pole Aitken basin Largest, deepest (over 12 km) impact crater (56° 5, 180° E; 2,500 km) known in the solar system; oldest basin on the Moon; absolute age unknown (4.3 Gyr??) A Fundamentals of selenography 235 Other surface features Name and Location Description Apennine Bench Refers to a relatively elevated region near (25-28° N, 0-10° W) Archimedes and just inside the rim of Imbrium basin; includes light-toned Apennine Mountains Large mountain chain making up the southeast­ (15-30° N, 10° W-50° E) ern rim of the Imbrium basin Cayley plains Light-toned, smooth highland plains, first de­ fined in the central near-side but having moon­ wide distribution; probably a form of impact ejecta from the youngest major basins; may cover ancient mare lavas in some areas Cordillera Mountains Arcuate mountain chain that makes up the rim (10-35° 5,80-90° W) of the Orientale basin Hadley-Apennines Informal name given to the region of the Apollo (26° N,4° W) 15 mission exploration; includes mare, Hadley Rille, and Apennine highlands Hadley Rille See Rima Hadley Marginis swirls Light-toned swirls north of Mare Marginis; ori­ (15° N, 90° E) gin unknown Marius Hills Complex area of small domes, cones, and sinu­ (10-15° N, 50-60° W) ous rilles in Oceanus Procellarum; the dome-like swell may indicate that this region is a large lu­ nar shield volcano Reiner Gamma Bright, swirl-like deposit in Oceanus Procel­ (7° N, 590 W) larum; origin unknown Rima Bode II Cleftlike vent and linear trench outline vent sys­ (13 0 N,4° W) tem for a large, regional blanket of dark volcanic ash Rima Hadley Long sinuous rille starting in the highlands and (25 0 N,3° W) emptying into the maria; probably a lava chan­ nel and/or tube Riimker Hills Complex of cones and domes in Oceanus Procel­ (41 0 N,58° W) larum, similar to Marius Hills but much smaller Taurus-Littrow Informal name given to the region of the Apollo (20 0 N, 31 0 E) 17 mission exploration; includes mare, dark mantle, and the highlands of the Serenitatis basin Tranquillity Base Site, in Mare Tranquillitatis, of man's first land­ W N,23° E) ing on the Moon, Apollo 11, July 20,1969 236 Fundamentals of selenography Figure A.1 The near-side of the Moon.