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Observations - Lunar 100


		Images are arranged in order of the main lunar features within the image that are included in the Charles Wood's Lunar 100. Some images are repeated on more than one occasion because they contain more than one feature on the list. Where appropriate, reference is given to the relevant chart in Antonin Rükl's 'Atlas of the Moon' and to corresponding chart and grid reference in 'The Hatfield SCT Lunar Atlas' by Jeremy Cook. A cross reference is also made to other feature on Lunar 100 that are either notably similar or contrasting features (in orange) or are nearby, geologically related or optimally viewed under the same libration or lighting conditions (in pale orange).

		To see a list of imaged lunar features ordered alphabetically click here
		You can see a map of the location of the Lunar 100 by clicking on the thumbnail image.

		*To view a picture click on the thumbnail image.*

		L1 Moon				Large Satellite
		Diameter = 3,476km
						The largest planet/satellite ratio in the solar system. (Pluto excepted). Distance 384,400 Km, Diameter 3,476 Km. Thought to be the product of a collision between a proto-earth and another Mars-sized body about 4.6 billion years ago. Its angular diameter is just 0.5 degrees. All other 99 objects are contained within that half degree.

		L2 Earthshine				Twice reflected sunlight
		Diameter = 3,476km
						Twice reflected sunlight illuminating the dark side of the moon. The old moon in the arms of the new.

		L3 Mare/highland dichotomy				Two materials with distinct compositions
		Diameter = 3,476km
						Even without an optical aid there is a readily apparent dichotomy in that the face of the moon contains dark patches against a generally bright surface. The dark areas are the mare and are the result of an upwelling of basalt lava from within the Moon's mantle to fill impact basins created early in its history. The bright surface is mainly Anorthosite, a light frothy rock which floated as the molten moon differentiated and heavier material sank to form the core and mantle.

		L4 Apennines				Imbrium basin rim
		Lat. 18.9^oN Lon. 3.7^oW Length = 580 km				Rükl 22 Hatfield 1
						Part of the Imbrium basin rim. An Arcuate range of mountains forming the south eastern quadrant of the basin. The Apennines were formed from the ejecta that was excavated from the basin and they tower over the mare up to five kilometres high. They are the finest example of its type on the nearside of the moon. Mons Huygens is the highest point on this range and stands at 5,400 m (16,400 ft) high. Apollo 15 landed very close to this mountain range.

		L5 Copernicus				Archetypal large complex crater
		Lat. 9.7^oN Lon. 20.1^oW Diameter = 93 km				Rükl 31 Hatfield 5(e4) see also L69, L74
						An archetypal large complex crater. Situated just south of the Imbrium basin, some of its ejecta and conspicuous rays overlap onto the Imbrium mare. It has high multiple central peaks and exhibits terraced walls. Copernicus is one of the more prominent craters on the moon. It is a perfect example of a fresh complex crater structure, exhibiting terraced walls and a central peak. It is also surrounded by a huge mantle of material that was ejected during its formation



		L6 Tycho				Large rayed crater with impact melts
		Lat. 43.4^oS Lon. 11.1^oW Diameter = 102 km				Rükl 64 Hatfield 10(d5)
						A prominent young (110 million years old) crater on the Moon with a ray system that extends almost over the complete near side. It also has a dark ring of impact melt material extending about two crater widths. Even that substantial amount of time is not enough to allow the 'gardening' effect of solar wind and micro meteorites to fade out the rays and halo. Its extensive rays are quite prominent at full moon.

		L7 Altai Scarp (Rupes Altai)				Nectaris basin rim
		Lat. 24.3^oS Lon. 22.6^oE Length = 427 km				Rükl 57 Hatfield 15(h2)
						The rim of the Nectaris basin is an arcuate range of mountains, up to 4 km high, on the south-western corner of the basin. Much of the remainder having been obliterated by large impacts.

		L8 Theophilus, Cyrillus, Catharina				Crater sequence illustrating stages of degradation
		Lat. 13.2^oS Lon. 24.0^oE Diameter = 110 km				Rükl 46,57 Hatfield 13(45)
						A magnificent chain of three similar-sized craters which are of various ages and consequently in various stages of degradation. Theophilus is the youngest crater which still shows many of the details including a well-defined central peak. Cyrillus is older and has been partially filled with magma. Catharina is the oldest. Magma has filled it to the point where the central peak is no longer visible.

		L9 Clavius				Lacks basin features in spite of its size
		Lat. 58.5^oS Lon. 14.1^oW Diameter = 245 km				Rükl 72 Hatfield 10(d3) see also L94, L96
						Large crater bordering on basin status. Located in the southern highlands it's only ever seen at an oblique angle and it's centre appears higher than it's surrounding walls due to its size and the moon's curvature. Also famous as the fictional moon base from 2001 A Space Odyssey.

		L10 Mare Crisium				Mare contained in large circular basin
		Lat. 18.0^oN Lon. 59.0^oE Diameter = 540 km				Rükl 26,27,37,38 Hatfield 3 see also L12
						Mare Crisium (Sea of Crisis) is a medium sized basin that is the only one on the near side of the Moon to be completely self contained. Well out to the eastern limb it is best seen just after new Moon when it is the first mare to be uncovered by the lunar dawn. l

		L11 Aristarchus				Very bright crater with dark bands on its walls
		Lat. 23.7^oN Lon. 47.4^oW Diameter = 40 km				Rükl 18 Hatfield 7(d8) see also L17, L 22, L86
						One of the brightest near face craters, but with dark bands on its inner walls. The crater is in Procellarum at the edge of an unusual uplifted plateau of volcanic origin. The inner walls have formed terraces which are covered with glassy fall back impact melt.

		L12 Proclus				Oblique-impact rays
		Lat. 16.1^oN Lon. 46.8^oE Diameter = 28 km				Rükl 26 Hatfield 3(d5) see also L10, L25
						This very bright young crater is unusual because of its ray patterns which show that the impacting article approached at an angle of less than 15 degrees from the surface. For a wide range of impact angles, the material ejected when a crater forms will spread out uniformly in all direction, as seen in craters like Tycho or Copernicus. However, when the impact angle is very low, the ejecta pattern is more directional.

		L13 Gassendi				Floor-fractured crater
		Lat. 17.6^oS Lon. 40.1^oW Diameter = 101km				Rükl 52 Hatfield 11(c4)
						Gassendi is fine example of a floor fractured crater. The fracturing of the floor is believed to be caused by upward pressure of magma below the crater as it takes advantage of the weak spot in the crust. Gassendi is located on the northern edge of Mare Humorum.

		L14 Sinus Iridium				Very large crater with missing rim
		Lat. 45.0^oN Lon. 32.0^oW Diameter = 260 km				Rükl 10 Hatfield 6(f4)
						Sinus Iridium (Bay of Rainbows) sits on the edge of the Imbrium basin and has been embayed by the lava flows that created the mare. Although Sinus Iridum appears to be a bay on the northeast shore of Mare Imbrium, it is actually a crater that is tilted by subsidence into the Imbrium impact basin, then later filled with mare material. The "horns" of the bay are Promontorium Heraclides and Promontorium Laplace.

		L15 Straight Wall (Rupes Recta)				Best example of a lunar fault
		Lat. 21.8^oS Lon. 7.8^oW Length = 134 km				Rükl 54 Hatfield 9(b3)
						A 120 km fault line on the eastern side of Mare Nubium. The mare is estimated to be some 450 metres higher on the eastern side of the fault line where the western side has slipped away.



		L16 Petavius				Crater with domed and fractured floor
		Lat. 25.1^oS Lon. 60.4^oE Diameter = 188 km				Rükl 59 Hatfield 15(d2)
						Large crater near the south eastern limb. The outer wall is unusually wide in proportion to its diameter, and has a double-rim along the south and west sides. The height of the rim varies by as much as 50% and a number of ridges radiate outward from the rim. The convex crater floor displays a rille system named the Rimae Petavius. A deep fracture runs from the peaks toward the southwest rim of the crater.

		L17 Schröter's Valley				Giant sinuous rille
		Lat. 26.2^oN Lon. 50.8^oW Length = 168 km				Rükl 18 Hatfield 8(e2) see also L11, L22, L86
						A giant sinuous rille closely associated with the Aristachus Plateau. Its origins are within the plateau at the Cobra head and the magma that carved the channel flowed out into Procellerum.

		L18 Mare Serenitatis dark edges				Distinct mare areas with different compositions
		Lat. 17.8^oN Lon. 23.0^oE				Rükl 34 Hatfield 1(b6,c4)
		Not yet imaged				All mare are formed when magma has risen up through the crust and flooded an impact crater, but there is no rule that says this flooding can happen only once. Look at Mare Serenitatis (Sea of Serenity) and notice that the outer edge of the mare material is darker than the central area. Thus, at least two magma flows have happened here, and with two different types of material.

		L19 Alpine Valley (Vallis Alpes)				Lunar graben-
		Lat. 49.0^oN Lon. 3.0^oE Length = 165 km				Rükl 4 Hatfield 2(f4) see also L23, L83
						Graben are formed when the crust gets stretched and breaks apart. Sometimes a block between two faults will drop down to form the graben, sometimes lava will well up into the crack and form the flat bottom of the valley. In the case of Alpine Valley, it was probably lava that welled up into the crack. There is a rille (collapsed lava tube) that runs the length of this valley that is a real challenge to observe.

		L20 Posidonius				Floor-fractured crater
		Lat. 31.8^oN Lon. 29.9^oW Diameter = 95 km				Rükl 14 Hatfield 3(g8) see also L33
						Easy to observe members of a less common class of crater, the floor-fractured crater. These craters retain some of their original features, but have a fractured floor that is usually higher in the middle. They are modified when magma pushed up through the area of the crust weakened by the original impact event. The magma raises the floor of the crater, causing it to buckle and split.

		L21 Fracastorius				Crater with subsided and fractured floor
		Lat. 21.5^oS Lon. 32.2^oE Diameter = 112 km				Rükl 58 Hatfield 15(g4)
		Not yet imaged				A lava-flooded remnant of an ancient lunar impact crater located at the southern edge of Mare Nectaris. The northern wall of this crater is missing, with only mounds appearing in the lunar mare to mark the outline. The lava that formed Mare Nectaris also invaded this crater, so the structure now forms a bay-like extension. The remaining the rim is heavily worn and covered in lesser craters.

		L22 Aristarchus Plateau				Uplifted region mantled with pyroclastics
		Lat. 26.0^oN Lon. 51.0^oW Diameter = 200 km				Rükl 44,45 Hatfield 8(d2) see also L11, L17, L86
						A unique, 170 by 200 km diamond shaped plateau which is darker than the surrounding mare and the source of the Schröter's valley (L17), the largest rille on the near face of the moon. On photographs it shows up brown in colour. Also the source of various claims of Transient Lunar Phenomena (TLP)

		L23 Mons Pico				Isolated Imbrium basin-ring fragment
		Lat. 45.7^oN Lon. 8.9^oW Diameter = 25 km				Rükl 11 Hatfield 6(b4) see also L19, L83
						This peak forms part of the surviving inner ring of the Imbrium basin. This ring continues to the northwest and with the Montes Teneriffe and Montes Recti ranges. It rises to a height of only 2.4 km. A smaller peak to the south of Mons Pico is designated Pico Β. This region of the mare is notable for a number of wrinkle ridges.

		L24 Hyginus Rille				Rille containing rimless collapse pits
		Lat. 7.4^oN Lon. 7.8^oE Length = 226 km				Rükl 34 Hatfield 1(f3) see also L29, L35
						This beautiful rille valley that contains a large collapse pit at the breakpoint near the middle.

		L25 Messier and Messier A				Oblique ricochet-impact pair
		Lat. 1.9^oS Lon. 47.6^oE Diameter = 11 km				Rükl 48 Hatfield 15(d8) see also L12
		Not yet imaged				It is theorized that Messier crater was formed by an impact at a very low angle, and that 'Messier A' (which is oriented at right angles to Messier) was formed following a rebound by the impacting body. This may also explain the asymmetrical ray system. There is a dark streak in the centre of each crater. Two prominent rays extend westward from the rim of 'Messier A' for over 100 kilometres.

		L26 Mare Frigoris				Arcuate mare of uncertain origin
		Lat. 56.0^oN Lon. 1.4^oE Length = 1,600 km				Rükl 2,6 Hatfield 2 see also L26
		Not yet imaged				An arcuate mare near the top of the northern hemisphere. It is concentric with the northern third of the Imbrium basin. Its origin is uncertain, but speculation allows the possibility of it being part of an earlier impact basin, Gargantua.

		L27 Archimedes				Large crater lacking central peak
		Lat. 29.7^oN Lon. 4.0^oW Diameter = 83 km				Rükl 12,22 Hatfield 5(b8)
		Not yet imaged				A prominent crater near the Apennine mountains, but lacking the characteristic central peak that a crater of this size should have. It has probably been engulfed by the lava flow that has filled the crater's floor.

		L28 Hipparchus				Subject of first drawing of a single crater
		Lat. 5.5^oS Lon. 4.8^oE Diameter = 150 km				Rükl 44,45 Hatfield 13(e7)
		Not yet imaged				Hipparchus is an old crater with some craterlets within it. The largest crater within its rim is Horrocks. There is also part of a faint 'ghost' crater on Hipparchus's floor. Hipparchus also has historical significance being the subject of the first known sketch of a single lunar feature, done by Robert Hooke in 1665.

		L29 Aridaeus Rille				Long linear graben
		Lat. 6.4^oN Lon. 14.0^oE Diameter = 250 km				Rükl 34 Hatfield 1(d2) see also L24, L35
						This rille valley is thought to have been formed when a section of the Moon's crust sank down between two parallel fault lines (making it a graben or fault trough). It is a relatively young lunar feature, with few craters or other features overlying it.

		L30 Schiller				Possible oblique impact
		Lat. 51.9^oS Lon. 39.0^oW Diameter = 180 km				Rükl 71 Hatfield 10(g4) see also L37, L59
						Schiller appears to be a fusion of two or more craters. The crater rim is well-defined, with a terraced inner wall and a slight outer rampart. At the southeast end, a smaller crater is connected to Schiller by a wide valley. There are some bright patches that are clearly visible under a high sun angle. A double-ridge lies along the centre of the northwest crater floor, forming a nearly linear formation that divides the floor in half.

		L31 Taruntius				Unusual young floor-fractured ray crater
		Lat. 5.6^oN Lon. 46.5^oE Diameter = 56 km				Rükl 37 Hatfield 3(d2)
		Not yet imaged				The surface about Taruntius has an unusual number of ghost-craters and lava-flooded features. The outer rim is shallow, but forms a veined complex rampart, especially to the N and SW. The interior has an unusual concentric inner rim that is heavily worn and irregular. There are slender rilles that are concentric to the rim. The crater has a pair of faint dark patches of volcanic ash. One is located south of the central peak and the other on the sides of the northern rim.

		L32 Arago Alpha and Beta				Volcanic domes
		Lat. 6.2^oN Lon. 21.46^oE Diameter = 26 km				Rükl 35 Hatfield 1(c2) see also L53
		Not yet imaged				The rim of Arago has a bulge in the western wall. There is a central ridge that runs toward the north wall. To the north is a large lunar dome designated Arago α. A similar-sized lunar dome is located an equal distance to the west, designated Arago β.

		L33 Serpentine Bridge (Rimae.Plinius)				Basin inner-ring segment
		Lat. 27.3^oN Lon. 25.3^oE Length = 124 km				Rükl 24 Hatfield 1(c4) see also L20
		Not yet imaged				When the sun is setting on the eastern shore of Mare Serenitatis, the shadows cast by the Serpentine Ridge makes it stand out, revealing what appears to be a snake headed north.

		L34 Lacus Mortis				Strange crater with rille and ridge
		Lat. 45.0^oN Lon. 27.2^oE Diameter = 152 km				Rükl 14 Hatfield 2(b4)
						A plain of basaltic lava flows in the north eastern part of the Moon. To the south is the Lacus Somniorum, separated from this mare by the joined Plana-Mason crater pair, and a strip of uneven surface. Located prominently just to the east of the mid-point of this feature is the Bürg crater. The western part of the Lacus Mortis contains an extensive system of criss-crossing rilles collectively designated Rimae Bürg.

		L35 Triesnecker Rilles				Rille Family
		Lat. 4.3^oN Lon. 4.6^oE Length = 206 km				Rükl 33 Hatfield 1(f2) see also L24, L29
		Not yet imaged				Most rilles are sinuous, linear or arcuate. But the rilles near Triesnecker aren't any of these. They are mostly narrow and straightish with some tight curves. They are not associated with volcanic features. These are unusual, maybe unique rilles. Because some of the rilles cut across other ones there must be an age progression; in general the thinner rilles seem to be older than the wider, more pronounced ones.

		L36 Grimaldi basin				A small two-ring basin
		Lat. 5.5^oS Lon. 68.3^oW Diameter = 140 km				Rükl 39 Hatfield 11(g7) see also L 52, L77, L80
		Not yet imaged				The inner wall has been so heavily worn and eroded by subsequent impacts that it forms a low, irregular ring of hills, ridges and peaks, rather than a typical crater rim. The floor forms a flat, relatively smooth and featureless surface with a particularly low albedo. Beyond the basin are the scattered remnants of an outer wall. Rimae Grimaldi and Rimae Riccioli Grimaldi has a history of transient lunar phenomena.

		L37 Bailly				Barely discernible basin
		Lat. 66.5^oS Lon. 69.1^oW Diameter = 303 km				Rükl 71 Hatfield 10(g2) see also L30, L59, L 94, L96
						Bailly's crater floor is covered with a multitude of ridges and craters. The outer ramparts are eroded and in some places have been worn away. Any central peak is no longer discernible. Due to its current condition, observers have termed this feature a 'field of ruins'. The south-eastern part of the crater is home to Bailly A and Bailly B. These craters overlap, and Bailly A lies across the rim.

		L38 Sabine and Ritter				Possible twin impacts
		Lat. 1.7^oN Lon. 19.7^oE Diameter = 30 km				Rükl 35 Hatfield 1(c1) see also L50, L90, L93
		Not yet imaged				The two rims are separated by a narrow valley only a couple of kilometres wide. The interior is irregular with several low ridges. To the northwest of Ritter is a system of rilles designated Rimae Ritter. The interior floor of Sabine has a pair of small craterlets and a central rise. There is a ridge at the western edge of the floor that is concentric with the inner wall.

		L39 Schickard				Crater floor with Orientale basin ejecta stripe
		Lat. 44.3^oS Lon. 55.3^oW Diameter = 206 km				Rükl 62 Hatfield 12(e5) see also L43, L97
						A walled-plain with a worn rim overlain by smaller impact craters. The Schickard crater floor has been partially flooded, leaving only the southwest portion uncovered and rough-textured. The floor is marked with a triangular band of lighter-albedo material, leaving relatively darker patches in the north and southeast. This feature is more prominent when the sun is at a relatively high angle.

		L40 Janssen Rille				Rare example of a highland rille
		Lat. 45.4^oS Lon. 39.3^oE Diameter = 199 km				Rükl 67,68 Hatfield 16(f5)
						A heavily worn crater marked by lesser impacts. The wall forms a distinctive hexagonal shape with a slight curvature at the vertices. The prominent Fabricius crater lies entirely within the outer wall. In the south two-thirds of the Janssen crater can be discerned the remains of a large, concentric crater (the wall of which is overlaid by Fabricius) the floor of which contains a rille system named the Rimae Janssen.

		L41 Bessel ray				Ray of uncertain origin near Bessel
		Lat. 21.8^oN Lon. 17.9^oE				Rükl 24 Hatfield 1(d5)
		Not yet imaged				The crater of origin of the Bessel ray is still uncertain. It is not from the crater Bessel because it does not radiate from the centre of the crater. It may be from nearby Menelaus, but this crater seems to be from an oblique impact that ejected material in almost the opposite direction. Another possibility is Tycho, which is 2000 km away, but none of Tycho's other rays come close to radiating this far.

		L42 Marius Hills				Complex of volcanic domes and hills
		Lat. 12.5^oN Lon. 54.0^oW Diameter = 125 km				Rükl 28,29 Hatfield 7(e5) see also L57
						The greatest concentration of volcanoes on the Moon, with morphology also being different from elsewhere. A mare ridge is interpreted as part of the inner ring of the Procellarum Basin that may have provided a deep-seated conduit for magma. The many steep-sided cones in the Marius Hills have been identified as being partly made of pyroclastics. More gently-sloped mare domes are found at one end of the Marius Rille.

		L43 Wargentin				A crater filled to the rim with lava or ejecta
		Lat. 49.6^oS Lon. 60.2^oW Diameter = 84 km				Rükl 70 Hatfield 12(e5) see also L39, L97
						The interior is completely filled up to the edge of its rim by a basaltic lava flow, so that it forms a raised plateau. Since this occurred, some ejecta has been deposited across the top, giving the surface a higher albedo than is typical for basalt. The rim is worn and overlain by a few small craters. The outer wall are 0.3 km above the surrounding terrain. A spoked pattern of wrinkle ridges can be seen on the surface.

		L44 Mersenius				Domed floor cut by secondary craters
		Lat. 21.5^oS Lon. 49.2^oW Diameter = 84km				Rükl 51 Hatfield 11(e3) see also L91
						The rim of Mersenius is heavily worn, especially in the low northern section. 'Mersenius N' lies across the southwest rim. The interior has been flooded by basaltic lava, which bulges upward forming a domed shape with an estimated height 450 metres higher than the floor edges. This was formed by lava upwelling beneath the surface. At least two faint rilles lie along the floor. To the east is Rimae Mersenius.

		L45 Maurolycus				Region of saturation cratering
		Lat. 42.0^oS Lon. 14.0^oE Diameter = 114 km				Rükl 66 Hatfield 14(d6) see also L55
						Maurolycus is joined at the southeast rim by the smaller Barocius crater. The outer wall of Maurolycus are tall, wide, and terraced; most notably in the eastern part. To the southeast it is joined to what has the appearance of an overlain crater rim. 'Maurolycius F' lies across the northwest rim, and that part of the crater floor is more rugged than the remainder.

		L46 Regiomontanus central peak				Possible volcanic peak
		Lat. 28.0^oS Lon. 0.6^oW Diameter = 108 km				Rükl 55 Hatfield 13(g2)
		Not yet imaged				The rim is irregular, mountainous and oval in outline. The walls on the south and west have been almost completely degraded. A ridge lies off centre to the northwest, with the small crater 'Regiomontanus A' at its summit. 'Regiomontanus A was once considered proof of volcanic activity on the Moon. However, this feature is actually an impact crater, and is offset slightly from the summit of the central peak.

		L47 Alphonsus dark spots				Dark-halo eruptions on crater floor
		Lat. 13.7^oS Lon. 3.2^oW Diameter = 119 km				Rükl 44 Hatfield 13(g5) see also L51, L72, L74
						The floor of this carter is fractured by an elaborate system of rilles and contains three smaller craters surrounded by a symmetric darker halo. These dark-halo craters are cinder cone-shaped and are believed to be volcanic in origin, although some think they were caused by impacts that excavated darker mare material from underneath the lighter lunar regolith.

		L48 Cauchy region				Fault, rilles and domes
		Lat. 10.5^oN Lon. 38.0^oE Diameter = 130 km				Rükl 36 Hatfield 3(e3)
		Not yet imaged				Cauchy is a small crater that is prominent at full moon due its high albedo. Just to the northeast of the crater is a 210 km rille named Rima Cauchy. South west of Cauchy is a 120 km fault named the Rupes Cauchy. South of Rupes Cauchy are two lunar domes designated Omega Cauchy and Tau Cauchy. They lie to the south and southwest of Cauchy crater respectively, each with a craterlet at the crest.

		L49 Gruithuisen Delta and Gamma				Volcanic domes formed with viscous lavas
		Lat. 36.3^oN Lon. 40.0^oW Diameter = 20 km				Rükl 9 Hatfield 8(c4)
						To the north of the crater Gruithuisen is a domed mountainous rise that is designated Mons Gruithuisen Gamma. To the east of this feature is another mountainous rise named Mons Gruithuisen Delta. Northwest of Gruithuisen crater is a concentrated cluster of several craterlets, which was most likely formed from a single body that broke up just prior to impact.

		L50 Cayley Plains				Light, smooth plains of uncertain origin
		Lat. 4.0^oN Lon. 15.1^oE Diameter = 15 km				Rükl 34 Hatfield 1(d2) see also L29, L64, L66, L67, L90, L93
		Not yet imaged				Apollo 16 landing site. A smooth plain of uncertain origin.

		L51 Davy crater chain				Result of comet-fragment impacts
		Lat. 11.1^oS Lon. 6.6^oW Length = 51 km				Rükl 43 Hatfield 9(b5) see also L47
						This string of 23 tiny craters that is not believed to be due to secondary cratering because it is not radial to a suitable source crater. The most likely cause is believed to be due to a body that broke apart prior to impact due to tidal effects.

		L52 Crüger				Possible volcanic caldera
		Lat. 16.7^oS Lon. 66.8^oW Diameter = 45 km				Rükl 50 Hatfield 11(g5) see also L77
		Not yet imaged				The most distinctive feature about this crater is very dark interior floor that is one of the lowest albedo features on the Moon. The surface has been covered in basaltic-lava and has only been exposed to a minimal amount of deposition from impact ejecta. The floor is nearly featureless, with only a tiny craterlet near the centre and few other even smaller impacts.

		L53 Lamont				Possible buried basin
		Lat. 4.4^oN Lon. 23.7^oE Diameter = 106 km				Rükl 35 Hatfield 1(c2) see also L32, L90
		Not yet imaged				Lamont is a low ridge that is most likely an impact feature. It has the shape of two roughly concentric but incomplete rings with an inner diameter of 60 km and an outer diameter of 120 km. (The official diameter is 75 km.) Ridges radiate away from the centre except in the east and west quadrants. The ridge is only a few hundred metres high, with a 5 km average width.

		L54 Hippalus Rilles				Rilles concentric to Humorum basin
		Lat. 24.5^oS Lon. 29.0^oW Length = 240 km				Rükl 52,53 Hatfield 9(f3)
		Not yet imaged				A fine example of arcuate rilles on the eastern shore of Mare Humorum. Rimae Hippalus is a series of concentric rilles that are easily seen in a small telescope. One of the wide rilles passes directly through the walls and across the floor of the partially submerged crater Hippalus.

		L55 Baco				Unusually crater floor and surrounding
		Lat. 51.0^oS Lon. 19.1^oE Diameter = 69 km				Rükl 74 Hatfield 14(c4) see also L45
		Not yet imaged				The rim and inner wall has been eroded and worn by countless minor impacts since the original formation of the crater. As a result any terraces have been worn smooth and the rim is overlaid by several tiny craterlets. The interior floor is nearly flat, with no characteristic central peak at the mid-point and no small craters of significance.

		L56 Mare Australe				A partially flooded ancient basin
		Lat. 49.8^oS Lon. 84.5^oE Diameter = 515 km				Rükl 76 Hatfield 16(e3)
		Not yet imaged				Mare Australe (the "southern sea") is located in the south eastern hemisphere overlapping the near and far sides of the Moon. Unlike most of the lunar maria, Mare Australe has an uneven surface that is marked by a number of crater impacts including Jenner and Lamb craters, which are flooded with basaltic-lava much like many of the other craters in this mare.

		L57 Reiner Gamma				Conspicuous swirl and magnetic anomaly
		Lat. 7.7^oN Lon. 59.2^oW Diameter = 70 km				Rükl 28 Hatfield 7(f4) see also L42, L100
						This feature has a higher albedo than the dark mare surface, with a diffuse appearance and a distinctive swirling, concentric oval shape. Related albedo features continue across the surface to the east and southwest, forming loop-like patterns. It is believed that the feature resulted from seismic energies generated by the impacts that created the large Tsiolkovskiy crater on the far side.

		L58 Rheita Valley (Vallis Rheita)				Basin secondary-crater chain
		Lat. 51.0^oS Lon. 42.0^oE Diameter = 515 km				Rükl 68 Hatfield 16(e6)
						This 30km wide valley appears to share a common origin with the Vallis Snellius to the northeast, as both are oriented radially with Mare Nectaris.

		L59 Schiller-Zucchius basin				Badly degraded overlooked basin
		Lat. 56.0^oS Lon. 45.0^oW Diameter = 335 km				Rükl 70,71 Hatfield 12(d3) see also L30, L37, L59
						Southwest of Schiller is an unnamed area of maria that this thought to be the remains of an ancient formation that has had its outer walls eroded away. A horse-shoe shaped mountainous rim arcs around from Schiller C to Segner then Schiller S. A worn scarp stretches from Phocylides to Zucchius to Schiller. These may be rim segments from a multi-ring basin. A slight depression surrounded by an indistinct ridge may be an inner ring.

		L60 Kies Pi				Volcanic dome
		Lat. 26.9^oS Lon. 24.2^oW Diameter = 45 km				Rükl 53 Hatfield 9(e2)
						Dome to SSW of crater Kies. Typical dome, summit crater, W of Kies (Nubium sea).

		L61 Mösting A				Crater close to centre of lunar near side
		Lat. 3.2^oS Lon. 5.2^oW Diameter = 13 km				Rükl 43 Hatfield 13(h8)
		Not yet imaged				Mösting is a small lunar crater that is located in the south eastern fringes of the Mare Insularum. The ruined crater Sömmering lies to the northwest. To the southeast is the large crater-bay of Flammarion. Mösting has a terraced inner wall and a small central hill at the mid-point of the floor. To the south-southeast lies the bowl-shaped 'Mösting A' crater.

		L62 Rümker Hills				Large volcanic dome
		Lat. 40.8^oN Lon. 58.1^oW Diameter = 70 km				Rükl 8 Hatfield 8(d5)
						Mons Rümker is an isolated volcanic formation, forming a large, elevated mound in the northern part of the Oceanus Procellarum. The mound climbs to 1,100 m above the surrounding plain. The mound has a concentration of 30.lunar domes—rounded bulges across the top, some of which contain a small craterlet at the peak. Mons Rümker is surrounded by a scarp that separates it from the adjacent mare.

		L63 Imbrium sculpture				Basin ejecta overlying Boscovich and Julius Caesar
		Lat. 11.0^oN Lon. 12.0^oE				Rükl 34 Hatfield 1(e3) see also L29, L92
		Not yet imaged				Surrounding the Imbrium Basin is a region blanketed by ejecta extending out 800 km. Also encircling the basin is a pattern of radial grooves called the Imbrium Sculpture, which have been interpreted as furrows cut in 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.

		L64 Descartes				Putative region of highland volcanism
		Lat. 11.7^oS Lon. 15.7^oE				Rükl 45 Hatfield 13(c5) see also L50, L66, L67, L90
						A heavily worn crater in the south-central highlands. The rim only survives in stretches and is completely missing in the north. The crater floor contains several ridges that are concentric with the surviving outer walls to the NW and SE. A section of the outer rim of Descartes has a higher albedo than the surrounding surface due to a strong magnetic anomaly 50 km to the north is the Apollo 16 landing site.

		L65 Hortensius domes				Dome field north of Hortensius
		Lat. 7.6^oN Lon. 27.9^oW Diameter = 10 km				Rükl 30 Hatfield 5(g3)
						To the north of the crater Hortensius is a collection of six lunar domes, many having a tiny craterlet at the summit. These are shield volcanoes that were formed by a highly-viscous type of lava. The domes are generally circular in form, with a diameter of 6-8 kilometres (4-5 mi), and rising as high as 400 meters (1300 ft). They are formed of the same material as the surrounding mare, although from a different process.

		L66 Hadley Rille				Lava channel near Apollo 15 landing site
		Lat. 25.0^oN Lon. 3.0^oE Length = 82 km				Rükl 22 Hatfield 1(f6) see also L4, L50, L64, L67, L90
						Mons Hadley is a massif in the northern portion of the Montes Apenninus. It has a height of 4.6 km and a maximum diameter of 25 km at the base. To the southwest of this is a valley that served as the landing site for Apollo 15. To the southwest of this valley is the slightly smaller Mons Hadley Delta with a height of about 3.5 km. To the west of these peaks is the sinuous Rima Hadley rille.

		L67 Fra Mauro formation				Apollo 14 landing site on Imbrium ejecta
		Lat. 3.6^oS Lon. 17.5^oW Diameter = 99 km				Rükl 42 Hatfield 9(c6) see also L50, L64, L66, L90
		Not yet imaged				An area of ejecta by characterized ridges a few hundred feet high that radiate from the Imbrium basin and are separated by undulating valleys. The ejecta blanket is now buried by rubble and lunar soil churned up by more recent meteoroid impacts. Debris may have come from as deep as 160 km below the original lunar crust. Apollo 14 landed in the hills north of Fra Mauro crater.

		L68 Flamsteed P				Proposed young volcanic crater.
		Lat. 3.0^oS Lon. 44.0^oW Diameter = 112 km				Rükl 22 Hatfield 7(d2)
						Ruined crater Flamsteed is the largish crater just inside the southern end of this ring. To its southeast is 10 km Flamsteed B, and on the floor of the ruined ring are 6 km Flamsteed D and 4 km Flamsteed K. The Surveyor 1 craft landed within the northeast rim of the buried 'Flamsteed P' feature, about 50 km north-northeast of the Flamsteed crater rim.

		L69 Copernicus secondary craters				Rays and craterlets near Pytheas
		Lat. 19.6^oN Lon. 19.1^oW Diameter = 4 km				Rükl 20 Hatfield 5(e6) see also L5, L74, L78, L95
		Not yet imaged				Secondary craters are usually in radial lines An arc of secondaries in this area must have been ejected as a flap of material. A peculiar feature in this area is a 30 km long patch of smooth mare material just west of the unnamed mountain below Erathosthenes. This is so lightly cratered by secondaries that it seems like it must be lavas younger than Copernicus. But the herringbone ridges from the line of secondaries over the smooth lavas show it is older than Copernicus.

		L70 Humboldtianum basin				Multi-ring impact basin
		Lat. 57.0^oN Lon. 80.0^oE Diameter = 650 km				Rükl 7 Hatfield 4(f7) see also L72
						A mare within the Humboldtianum basin, just to the east of Mare Frigoris. The basin material is of the Nectarian epoch, with the mare material being of the Upper Imbrian epoch. The lighter grey area to the southeast of the dark mare material is a region of hills within the basin. The rim of this basin forms a mountain range that can be seen under oblique lighting conditions.

		L71 Sulpicius Gallus dark mantle				Ash eruptions northwest of crater
		Lat. 19.6^oN Lon. 11.6^oE Diameter = 12 km				Rükl 23 Hatfield 1(e5)
		Not yet imaged				The arcing Sulpicius Gallus Rilles cut lavas exposed now only at the edges of Mare Serenitatis – the Menelaus, Plinius and Littrow rilles all occur on the same lavas. Darkness coats the Haemus Mountains near the rilles. This is one of the largest pyroclastic deposits on the Moon. The narrow rilles and crater chains run at right angles to the main rilles. These trace dikes that fed lava and ash to the surface.

		L72 Atlas dark-halo craters				Explosive volcanic pits on the floor of Atlas
		Lat. 46.7^oN Lon. 44.4^oE Diameter = 87 km				Rükl 15 Hatfield 4(g6) see also L47, L70, L74
						The wall of floor-fractured Atlas is terraced and the edge slumped, forming a sharp lip. The interior is rough and hilly and is lighter than the surroundings. There are two dark patches along the inner edge of the walls; one along the N edge and another besides the SE edges. The slender Rimae Atlas crosses the crater floor. Along the N and NE inner sides are some dark-halo craters, most due to eruptions.

		L73 Smythii basin				Difficult-to-observe basin scarp and mare
		Lat. 2.0^oS Lon. 87.0^oE Diameter = 740 km				Rükl 38,49 Hatfield 15(a7) see L100
						The mare material, which make up the floor of the mare, is a high aluminous basalt, and consists of Upper Imbrian basalt covered by Eratosthenian basalt. Neper is located to the north of the mare and makes up part of the southern rim of Mare Marginis. Just off to the northwest of the mare are the craters Schubert and 'Schubert B'. Kästner.is a e dark mare-filled crater at the southern edge of Smythii.

		L74 Copernicus H				Dark-halo impact crater
		Lat. 6.9^oN Lon. 18.3^oW Diameter = 5 km				Rükl 31 Hatfield 5(e3) see also L5, L47, L72
		Not yet imaged				A dark halo impact crater. The halo is likely black, glassy beads which originated as quickly chilled drops of magma from gas-rich explosive eruptions. This material was excavated from beneath lighter-hued surface lavas.

		L75 Ptolemaeus B				Saucer-like depression on the floor of Ptolemaeus
		Lat.8.0^oS Lon. 0.8^oW Diameter = 164 km				Rükl 44 Hatfield 13(g6) see also L92
		Not yet imaged				Within the diameter of the crater of Ptolemaeus, there are several craterlets. Ptolemaeus B is a very subtle saucer that requires the proper shadowing to reveal. Ptolemaeus is well known as a relatively flat-floor crater with saucers - probably buried craters. You can see low relief areas that suggest the fronts of flows - lava flows or ejecta surge flows.

		L76 W. Bond				Large crater degraded by Imbrium ejecta
		Lat. 65.3^oN Lon. 3.7^oE Diameter = 158 km				Rükl 4 Hatfield 2(f7) see L26
		Not yet imaged				An irregularly shaped walled plain. What remains of the outer rim has been eroded and reshaped until it now consists of little more than an outline of hills and mounts. The most prominent of these is a nearly linear range along the northwest rim, which is divided in half by the 'W. Bond A' crater. There are sections of rough terrain inside the northern rim. In the centre is a narrow rille that runs toward the eastern rim.

		L77 Sirsalis Rille				Procellarum basin radial rilles
		Lat. 15.7^oS Lon. 61.7^oW Length = 426 km				Rükl 39,50 Hatfield 11(f5) see also L52
		Not yet imaged				Rimae Sirsalis is in an unusual location for a rille. Most rilles are near the edge of maria, or inside them. Rimae Sirsalis cuts across highlands. It passes through craters, ranges of hills, and other small rilles. It is unclear how a lava flow followed such a path, and a variety of theories have been presented including tectonic activity, (making Rimae Sirsalis a fault) or that the groove is a collapsed dike.

		L78 Lambert R				A buried "ghost" crater
		Lat. 23.8^oN Lon. 20.6^oW Diameter = 54 km				Rükl 20 Hatfield 5(e7) see also L69, L95
		Not yet imaged				Lambert R is a ghost crater. It was inundated by Imbrium lavas. There was less lava initially over the rim, so when the overflow compressed with degassing, the rim showed again.

		L79 Sinus Aestuum				Eastern dark-mantle volcanic deposit
		Lat. 12.0^oN Lon. 3.5^oW Diameter = 290 km				Rükl 33 Hatfield 5(c4)
						The Bay of Billows forms a northeastern extension to Mare Insularum. The Sinus Aestuum is a level, nearly featureless surface of low albedo basaltic-lava that is marked by a few small impacts and some wrinkle ridges. The eastern border is formed by an area of irregular terrain that divides the bay from the Mare Vaporum to the east.

		L80 Orientale basin				Youngest large impact basin
		Lat. 19.0^oS Lon. 95.0^oW Diameter = 930 km				Rükl 50 Hatfield 11(h5) see also L36
						May be the youngest basin on the Moon and is believed to be slightly younger than the Imbrium Basin. Orientale is relatively unflooded by mare basalts, exposing much of the basin structure to view. The central portion is covered by a thin layer of mare basalt probably less than 1 km deep. The innermost rings are the inner and outer Montes Rook, and the outermost ring are the Montes Cordillera.

		L81 Hesiodus A				Concentric crater
		Lat. 30.1^oS Lon. 17.0^oW Diameter = 15 km				Rükl 54 Hatfield 10(e8) see also L84
						Hesiodus A is a concentric crater. There are 51 concentric craters logged by Charles Wood. They are all 2 to 20 km in diameter. They are proposed due to volcanic extrusion or volcanic extrusion, not sequential impacts.

		L82 Linné				Small crater once thought to have disappeared
		Lat. 27.7^oN Lon. 11.8^oE Diameter = 2.4 km				Rükl 23 Hatfield 1(e7) see also L89
		Not yet imaged				Linne is a subject of mystery in the 19th century. Thought to have disappeared. Proposed mechanisms were collapse, a lava flow, meteorite impact, or hoarfrost. It considered a typical small, simple crater about twice the of Earth’s Meteor Crater. The white surround is often easy see, but the pit can be difficult especially at high sun.

		L83 Plato craterlets				Crater pits at limits of detection
		Lat. 51.6^oN Lon. 9.4^oW				Rükl 3,4 Hatfield 6(b5) see also L19, L23
						Small craterlets seen under good conditions on the otherwise featureless flooded floor of Plato. Under good conditions four are visible with diameters of 2.1 to 3.2 km. Four more can be seen under very good conditions. With a large telescope and ideal conditions a total of 17 craterlets may be imaged.

		L84 Pitatus				Crater with concentric rilles
		Lat. 29.8^oS Lon. 13.5^oW Diameter = 97 km				Rükl 54 Hatfield 9(c1) see also L81
						An ancient floor-fractured crater with a complex heavily worn wall and encroached by lava flows. Near the middle is a low central peak( height of 0.5 km) that is offset to the northwest of centre. The crater floor contains low hills in the east and a system of slender clefts named the Rimae Pitatus. The larger and more spectacular of these rilles follow the edges of the inner walls, especially in the northern and eastern halves.

		L85 Langrenus rays				Aged ray system
		Lat. 8.9^oS Lon. 60.9^oE Diameter = 132 km				Rükl 49 Hatfield 15(c6) see also L73
		Not yet imaged				Large complex Eratosthenian-age crater near eastern limb with terraced walls and prominent central peak and a system of rays .

		L86 Prinz Rilles				Rille system near the crater Prinz
		Lat.20.7^oN Lon. 43.0^oW Length = 82 km				Rükl 19 Hatfield 8(d2) see also L11, L17, L22
		Not yet imaged				The Prinz Rilles are channels and collapsed tubes made by flowing lava. Sinuous rilles range up to 300 km long. They are about 10x wider and longer than their terrestrial counterparts, a function of low lunar gravity and less viscous lavas on the Moon. Vera is the source of the longest Prinz Rille and its pit is barely visible in a 6 inch telescope.

		L87 Humboldt				Crater with central peaks and dark spots
		Lat. 27.0^oS Lon. 80.9^oE Diameter = 189 km				Rükl 60 Hatfield 15(c1) see also L16, L56
		Not yet imaged				The rim of the Humboldt is low, worn, and irregular in outline and has an indentation along the SE rim where the Barnard crater intrudes. The central peak forms a range on the crater floor. The floor contains a network of clefts in radial spokes and concentric arcs. There are some dark patches located near the walls to the NE, NW and SE. Catena Humboldt is a chain of craters leading from the NW rim.

		L88 Peary				Difficult-to-observe polar crater
		Lat. 88.6^oN Lon. 95.3^oE Diameter = 104 km				Rükl 4,II see also L76
		Not yet imaged				The closest large crater to the north pole. At this latitude the crater interior receives little sunlight, and parts of the S floor remain permanently cloaked in shadow. The crater has an outward bulge along the NE rim. There is a gap in the SW rim, where it joins a slightly smaller worn crater formation. The outer rim of is worn and eroded, creating a rugged mountainous ring that produces long shadows across the floor.

		L89 Valentine Dome				Volcanic Dome
		Lat. 30.5^oN Lon. 10.1^oE Diameter = 30 km				Rükl 13 Hatfield 1(e7) see also L82
						A flat plateau that is all but invisible unless lighting conditions are just right. When the feature is illuminated by a low Sun, you can see a delicate rille or fault crossing the dome. Also visible are four small peaks that stick up from the middle and a clump of additional hills situated at the dome’s SW corner. The reason for this voluminous eruption is unknown.

		L90 Armstrong, Aldrin and Collins				Small craters near the Apollo 11 landing site
		Lat. 1.3^oN Lon. 23.7^oE Diameter = 3 km				Rükl 35 Hatfield 13(b8) see also L38, L53, L50, L64, L66, L67, L73, L90
		Not yet imaged				Three craters near Apollo 11 landing site.

		L91 De Gasparis Rilles				Area with many rilles
		Lat. 25.9^oS Lon. 50.7^oW Length = 134 km				Rükl 13 Hatfield 11(e2) see also L44
		Not yet imaged				A great fracture section around the crater of the same name, with a degree of complexity approaching that of Triesnecker. It's a bit harder to see, due to the rugged highland characteristics of the terrain, and the long shadows of the hills. There is some definite crosshatching, and places where the rilles cross mountains and valleys.

		L92 Gylden Valley				Part of the Imbrium radial sculpture
		Lat. 5.1^oS Lon. 0.7^oE Length = 109 km				Rükl 44 Hatfield 13(f7) see also L28, L61, L63, L75
						Long complex valley that forms part of the Imbrium radial sculpture.

		L93 Dionysius rays				Unusual and rare dark rays
		Lat. 2.8^oN Lon. 17.3^oE Diameter = 18 km				Rükl 35 Hatfield 1(d1) see also L29, L32, L38, L50
		Not yet imaged				Short dark rays that are most conspicuous to the west of the crater. Most visible when viewed near full moon Rays are thought to be localised dark volcanic ash or lava flow excavated by the impact that formed Dionysius.

		L94 Drygalski				Large south-pole region crater
		Lat. 79.3^oS Lon. 84.9^oW Diameter = 149 km				Rükl 72,IV Hatfield 10(e1) see also L9, L37, L96
		Not yet imaged				The outer rim of this crater has been worn and eroded leaving a rugged, mountainous ring that is overlaid in places by small craters. A small crater chain starts by the northern outer rim then arcs N toward Boltzmann. To the south are two or more small craters, forming a short valley. Portions of the floor are flat; the flattest parts are in the S and E sections of the interior. The surface is more rugged in the W, and is marked by several small craterlets.

		L95 Mare Procellarum				The Moon´s biggest basin?
		Lat. 23.0^oN Lon. 15.0^oW Diameter = 721 km				Hatfield 1,5,6,7,8,9,11
		Not yet imaged				Huge mare possibly caused by in-filling of putative massive Gargantuan basin. This 2,500 km wide basin would take up around 1/4 of the nearside of the Moon (including all Mare Imbrium) bound by northern edge of Mare Figoris and highlands south of Sinus Medi . Some have suggested outer rings with diameter of 3,200km bound by southern edge of Mare Nubium.

		L96 Leibnitz Mountains				Rim of South Pole-Aitken basin
		Lat. 85.0^oS Lon. 30.0^oE Length = 80 km				Rükl 73,V Hatfield 14(e1) see also L9, L37, L94
		Not yet imaged				The tallest lunar mountains sticking up above the limb are rim segments of the South Pole-Aitken basin. Continue an imaginary line from the centre of Moretus to a small fresh crater on the S rim of Newton A to see the massive peak (M1). M3 is to the right of M1 but not on the limb. The massive elongated mountain (with a small bright crater on its left side) beyond M1 on the limb is M5. The bump on the limb to the right is M4.

		L97 Inghirami Valley				Orientale basin ejecta see also L37, L39, L43
		Lat. 44.0^oS Lon. 73.0^oW Length = 145 km				Rükl 61 Hatfield 12(f5)
						NW of Inghirami crater is the wide Vallis Inghirmi, a wide, straight valley that is radial to the Mare Orientale impact basin. It has a length of about 140 km and ends at the northern edge of the crater.

		L98 Imbrium lava flows				Lava flows between Carlini and McDonald
		Lat. 32.8^oN Lon. 22.0^oW				Rükl 10 Hatfield 6(e2)
		Not yet imaged				Lobe-like lava flows best seen at very low sun angles.

		L99 Ina caldera				D-shaped young volcanic caldera
		Lat. 18.6^oN Lon. 5.3^oE Diameter = 3 km				Rükl 22 Hatfield 1(f5) see also L89
						Very difficult to observe 30 m deep pit in highland area behind the Appenine Mountains. May be formed by gases escaping from the Moon. Apollo’s super high resolution images reveal that the floor of Ina is filled with small delicate features that would have been destroyed by random micrometeorite cratering if the depression were older than a million years or so. Looks brighter imaged through a blue filter.

		L100 Mare Marginis swirls				Possible magnetic field-deposits
		Lat. 18.5^oN Lon. 88.0^oE Diameter = 18 km				Rükl 27,III Hatfield 3(a4) see also L10, L42, L73
						This mare has an irregular outline and appears to be fairly thin. Small circular and elongated features in the mare plains probably mark craters buried by <1000 to 1700 ft of lava. Mare Marginis seems to mark a low-lying region of the highlands where mare lavas were just able to reach the surface. The surface displays swirling high albedo areas. This is antipodal to Mare Orientale and may be associated with its formation.


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Last updated - 18th September 2010