X LACUS MORTIS 4 Directly north of Lacus Somniorum, Lacus Mortis is a small flat zonecontiguous to Mare Frigoris. It lies next to the Aristoteles and ExodusCraters and actually is a big ghost-crater. X LACUS SOMNIORIUM 4 It is a small flat zone scarcely connected with the Mare Serenitatis. Itlies north of the Tauro range. On its plain we can see several detailsand between the Grove and Mason craters, some fissures are observable. X MARE ANGUIS 4 It is a small sea on the eastern border of the Moon. In condition ofunfavorable libration it is practically invisible because of theperspective flatness. It lies on the border the Mare Crisium. X MARE CRISIUM 9 It is a closed dock, the only one on the visible side of the Moon. Itseems to have a very elliptical shape because of the perspective, withthe north-south axis that is much longer than the east-west one.Actually it is a nearly circular dock with the major axis in east-westdirection. It covers an area about 200,000 square kilometers, and thelenght of the axes is 440 km and 560 km. The surface of this sea is verydark, especially towards the eastern border. Among the several cratersthat we can see inside Mare Crisium, Picard is the largest. X X MARE FOECUNDITATIS 5 It is delimited on every side by craters of significant size: Vandelinusand Langrenus in the east, Gutemberg and Goclenius in the south-west. Onthe bottom there are not large craters but Messier deserves a particularnote for its curious comet-shaped rays. XXX MARE FRIGORIS 7 It is a large sea that has a very flat shape and lies in east-westdirection, immediately north of the Plato and Aristoteles craters. It isthe northeastern sea of the Moon. The ground is rather clear comparedwith the other lunar seas. There are two well visible craters in it:Protagoras and Galle. Mare Frigoris divides the region of Montes Alpesfrom the tablelands and from the highlands of the North Pole. X MARE HUMBOLDTIANUM 5 It is a dark plain. Its diameter is about 200 km. It lies on the easternborder of the Moon. It has a very flat shape because of the perspective.It is probably the remnant of a very ancient cirque. Its extension isabout 108,000 square kilometers. X MARE HUMORUM 6 It is a very well delineated sea, it is open in the north towardsOceanus Procellarum. On its borders there are many craters: Vitello inthe south, Hippalus in the east (which actually is a bay), Mersenius inthe west (together with a noteworthy system of rilles) and Gassendi inthe north. XX XX MARE IMBRIUM 6 It dominates the northwestern side of the Moon, it is the longestregular sea and it is delimited partly by the Alpes and the Appennines.Three big craters (Archimedes, Aristillus and Autolycus) are on itsbottom, and on its northern border one can see Plato, the famous craterwith the dark ground. X MARE MARGINIS 3 Small sea on the eastern side of the Moon next to Mare Crisium. It ispossible to observe it only in condition of favorable libration. X MARE NECTARIS 5 It is one of the first observable seas when the lunar phase ~raises~. Itlies directly south of Mare Tranquillitatis and it has an area of about90,000 square kilometers. The lava that covered it after its birth hadalso covered the ancient Fracastorius creater. XX MARE NUBIUM 5 It lies directly west of Ptolemaeus; on the southern border of MareNubium notice the pair Pitatus-Hesiodus. On the bottom of Mare Nubiumlies Bullialdus, a Copernicus in miniature. In the south-west there isthe Palus Epidemiarum, which actually is an extension of Mare Nubium. XX MARE SERENITATIS 8 It is the second widest sea behind Mare Imbrium. The Montes Haemus inthe south, the Caucasus in the north and the Tauro in the east clearlydefine its border. It is connected with Mare Imbrium and Mare Romer(caracteristic for its central peak surmounted by a small crater). Itssurface is relatively undulated, but it includes some jutting and highformations, like the one of Bessel. The surface is dark, like the one ofMare Imbrium, and is probably more ancient. X MARE SMYTHII 3 It is a small sea on the eastern border of the Moon, across the equator.It is possible to observe it only in conditions of favorable libration. X MARE SPUMANS 4 Small basin across the equator on the eastern border of the Moon, nextto Mare Foecunditatis. It is easily observable in conditions offavorable libration. X X MARE TRANQUILLITATIS 7 It is the most famous of the lunar seas, since the astronauts of theApollo 11 landed there on July 20, 1969. It is the third lunar basindimension-wise, behind Oceanus Procellarum and Mare Imbrium. It is aflat area of 360,000 square kilometers. It is located in the center ofthe visible hemisphere, so that it is easily identifiable. Its surfaceis rather clear and uniform, with many well visible craters. X MARE UNDARUM 4 Small basin directly north of the equator, on the eastern border of theMoon, close to Mare Foecunditatis. On its southern border a narrowpassage connects it with Mare Spumans. X X MARE VAPORUM 6 It is a small sea close to the Appenines range, among Sinus Aestum,Sinus Medii and Montes Haemus. It is rather small, but it is very famousbecause its surface is quite dark and on its borders there are importantcrateric complexes such as Boskovich and Manilius, beyond deep fracturessuch as the Rima Hyginus and the Rima Ariadeus. XX XX OCEANUS PROCELLARUM 10 It is the only lunar ocean. Its has an area of about 4,000,000 squarekilometers. It occupies a significant part of the western side of thevisible hemisphere and contains particulary bright craters such asAristarchus and Kepler. It is larger than the Mediterranean Sea, but itdoes not have the characteristic circular shape of most lunar seas. Itcould be the consequence of the overflow of Mare Imbrium into thedepression left by a more ancient formation dating back to the dawn ofthe history of the Moon. In condition of unfavorable libration seemsto reach the border of the Moon. X PALUS EPIDEMIARUM 5 This formation, that actually is a prolungation of Mare Nubium, is veryinteresting because it has a complicated system of rilles in theproximity of the Ramsden crater. On the border of Palus Epidemiarum liescrater Capuanus. X PALUS NEBULARUM 4 Small flat area between Mare Serenitatis and Mare Imbrium. It isconnected with Mare Imbrium in such an evident way as to seem aramification of it. It lies on the central meridian of the Moon. X PALUS PUTREDINIS 4 It lies between Mare Serenitatis and Mare Imbrium, right to thesouth-east of Archimedes. Southwards it is delimited by the Appennines.It lies astride the central meridian of the Moon. X X PALUS SOMNII 4 It is a little irregular sea and it presents an uncommon yellowish tint.It lies next to Mare Tranquillitatis and part of its border isformed by two rays departing from the quite near crater Proclus. X X SINUS AESTUM 5 It is a little sea that is separated from Mare Vaporum by the southernextremity of the Appennines. It lies east of Copernicus. The wonderfulcrater Eratosthenes is on its border. The plateau is relativelyundulatory and it does not contain noteworthy superficial details. X SINUS IRIDUM 9 It is a bay to the north-west of Mare Imbrium. Its western border isrepresented by the Jura range, that descends vertically to Sinus Iridumitself. It is clearly visible during the phase of crescent Moon, whenits floor is in the shade and Montes Jura are in the bright sunshine. The walls rise gradually from Mare Imbrium up to 8,000 meters, andarrive at Capo Laplace. Sinus Iridum has a black surface like MareImbrium, and is flat, so that it is easy to notice the Sinus and itsinterface with the plateau. X SINUS MEDII 4 It lies in the middle of the lunar disc, and its bottom is very smooth,interrupted only by the crater Bruce. It lies immediately north of thearea of the big craters (Ptolemaeus and others). X SINUS RORIS 5 It is the ideal continuation of Mare Frigoris, it delimits the westernregion of the Moon. Southwards it opens into Oceanus Procellarum. Itsurrounds Mare Imbrium. It is not very interesting. Among the minorstructures the Rumker hills can be observed. X MONTES ALPES 8 Like many other mountain ranges on the Moon, Montes Alpes surround asea. Their origin was a consequence of the impact that has created MareImbrium, because they lie immediately north of this big round basin.This mountain range is interrupted by the large cirque of Plato and byVallis Alpina. The highest mountain is Mt. Blanc, as on the Earth, buthere it reaches only 4,000 meters. The range has an extension of about200 km. X MONTES ALTAI 5 It is a mountain range that is about 3,300 meters high at its top, and440 km wide. It has originated from a long fissure and subsequentraising of the soil between the crater Piccolomini and Chatarina. Itlinks two tabelands that have different heights. X MONTES APPENNINES 10 To the south-east of Mare Imbrium, between Capo Fresnel and the craterErathostenes, we can see this mountain range that was obviouslyoriginated by an impact: the western side is steep and precipitous, withvarious terraces, like the inner border of many craters. The easternside is formed by a degrading slope that ends into Mare Serenitatis andinto Mare Vaporum. Its length reaches 950 km, while its highest peakis 5,500 meters high. In the tablelands on the range we can observe somedistorted and old craters like Serao and Marco Polo without any centralpeak and with a dark shelf. X MONTES CARPATUS 5 This modest mountain range was created by the impact which gave originto Mare Imbrium, which is divided by it from the Oceanus Procellarum. Wecan easily find it, because it lies just north of the crater Copernicus.It is 280 km long and 240 meters high. X MONTES CAUCASUS 6 It is a promontory that divides Mare Serenitatis from Palus Nebularum(3,650 m. high). This little mountain range can also be considered theextreme eastern offshoot of Montes Alpes. Also in this case the meteoricorigin of the mountains is evident, because they are steep on thewestern side and degrading in a light eastern slope. X MONTES HAEMUS 3 It is an eastern offshoot of Montes Appennines. It is not higher than1,500 m. X MONTES HARBINGER 4 It is a little mountain range made up of hills rather than of realmountains to the east of crater Aristarchus: its highest peak reachesonly 1,756 m. X MONTES HUYGENS 3 It is a massif 4,680 m high. It extends to the west of Montes Appenninestowards Mare Imbrium. X MONTES JURA 6 This little mountain range is situated on the northern edge of SinusIridum. Its origin can be considered as contemporary with that of MontesAlpes, Montes Caucasus, Montes Appennines and Montes Carpatus: all ofthem quite surely originated from the impact that created Mare Imbrium.It reaches a maximum height of 3,800 m. XX MONTES RECTI 3 It is a little mountain range near Sinus Iridum and it is about 2,000 mhigh. X MONTES RIPHAEUS 3 In the middle of Oceanus Procellarum, west of the cirque Fra Mauro, wefind this mountain range that is 180 km long and 1,200 m high. X MONTES ROOK 4 The outline of this mountain range can be noticed on the extreme westernedge of the Moon. It is probably the highest on the Moon: it reaches aheight of 7,900 m. X MONTES SPITZBERGEN 4 It is a little mountain range in Mare Imbrium, to the north of craterArchimedes. Rather than mountains, they should be called hills: thehighest peaks reach only 1,400 m. X MONTES TAURUS 4 This 3,000 m high chain is situated on the eastern border of MareSerenitatis. It is famous because it was explored in the last Apollomission. X MONTES TENERIFFE 3 To the south of the big cirque of Plato there are these six hillocks,the height of which varies between 1,000 and 1,450 m. X MONTES URAL 3 It is a little mountain range that departs from Montes Riphaeus in themiddle of Oceanus Procellarum. Its highest peaks reach 1,700 m. X RIMA ARIADAEUS 6 It is a long crevice that seems to depart from the homonymous crater. Itis about 280 km long and it stretches in the east-west direction. It isinterrupted in some points, but on the average it is almost 500 m deepand 4,500 m wide. In the west it branches out into various minorfissures that meet Rima Hyginus. It was discovered by Schroter in 1792. X RIMA HYGINUS 7 It is one of the most spectacular crevices that exist on the visibleface of the Moon. It is practically a sequence of crater shapeddepressions and it is about 1,700 m long. It departs from MonsSchneckenberg, that is curiously spiraliform. At the point of thehomonymous crater, the cleft turns with quite clear a curve to arrive atthe crater Triesnecker. X RUPES RECTA 6 It is one of the most famous geologic formations of the Moon. It is acrevice that is one hundred km long and 150 m deep. It can be located inMare Nubium. When the terminator is close, the grazing light makes itvisible in a particular way, like a clear cut on the flat surface ofMare Imbrium. X VALLIS ALPINA 5 This crevice departs from about the middle of Montes Alpes. It linksMare Imbrium with Mare Frigoris. It is about 10 km wide and 130 km long.A little winding crack can be noticed inside. The little brillantcrevice Trouvelot can be seen nearby. X X VALLIS RHEITA 3 It is a valley about 180 km long and 24 km wide, departing from thehomonymous crater in direction south-east. X VALLIS SCHROTER 3 It is a fissure 3 to 8 km wide and 190 km long. It departs from craterAristarchus. X RUMKER 4 It is a tableland west of Montes Jura. It can be seen only when it isnear the terminator because it is close to the lunar border. It isconsidered the biggest structure in the shape of a lunar dome.
