located_on_astronomical_body esclangon 
Lacus Bonitatis ( Latin for " Lake of Goodness ") is a small lunar mare that lies to the northwest of the prominent crater Macrobius . Further to the north of Lacus Bonitatis is the Montes Taurus mountain range . Montes Taurus is a rugged , jumbled mountainous region on the ___MASK87___ . It is located to the east of the Mare Serenitatis , in the northeastern quadrant of the ___MASK87___ ' s near side . Coordinates of their center are , and their extent is about 170 km . Terrain or relief ( also topographical relief ) is the vertical and horizontal dimension of the land surface . When relief is described underwater , the term bathymetry is used . The Latin Word " Terra ( The root word of terrain )," is " ___MASK10___ ." Water is a transparent and nearly colorless chemical substance that is the main constituent of ___MASK10___ ' s streams , lakes , and oceans , and the fluids of most living organisms . Its chemical formula is HO , meaning that its molecule contains one oxygen and two hydrogen atoms , that are connected by covalent bonds . Water strictly refers to the liquid state of that substance , that prevails at standard ambient temperature and pressure ; but it often refers also to its solid state ( ice ) or its gaseous state ( steam or water vapor ). It also occurs in nature as snow , glaciers , ice packs and icebergs , clouds , fog , dew , aquifers , and atmospheric humidity . Mare Tranquillitatis ( Latin for Sea of Tranquility or Sea of Tranquillity ( see spelling differences ) is a lunar mare that sits within the Tranquillitatis basin on the ___MASK87___ . The mare material within the basin consists of basalt formed in the intermediate to young age group of the Upper Imbrian epoch . The surrounding mountains are thought to be of the Lower Imbrian epoch , but the actual basin is probably Pre - Nectarian . The basin has irregular margins and lacks a defined multiple - ringed structure . The irregular topography in and near this basin results from the intersection of the Tranquillitatis , Nectaris , Crisium , Fecunditatis , and Serenitatis basins with two throughgoing rings of the Procellarum basin . Palus Somni , on the northeastern rim of the mare , is filled with the basalt that spilled over from Tranquillitatis . Sinus Amoris ( latin for " Bay of Love ") extends northward from the northeast end of the Mare Tranquillitatis . It is located at selenographic coordinates 18 . 1 ° N , 39 . 1 ° E , and lies within a diameter of 130 km . To the north of the bay are the jumbled Montes Taurus peaks . The lunar maria ( singular : mare ) are large , dark , basaltic plains on ___MASK10___ ' s ___MASK87___ , formed by ancient volcanic eruptions . They were dubbed " maria ", Latin for " seas ", by early astronomers who mistook them for actual seas . They are less reflective than the " highlands " as a result of their iron - rich compositions , and hence appear dark to the naked eye . The maria cover about 16 percent of the lunar surface , mostly on the side visible from ___MASK10___ . The few maria on the far side are much smaller , residing mostly in very large craters . The traditional nomenclature for the ___MASK87___ also includes one " oceanus " ( ocean ), as well as features with the names " lacus " ( lake ), " palus " ( marsh ), and " sinus " ( bay ). The last three are smaller than maria , but have the same nature and characteristics . Esclangon is a lunar crater that is located in the rugged terrain to the northwest of the prominent crater Macrobius , and east of Sinus Amoris . Just to the west - southwest is the crater Hill . Lacus Bonitatis , the Lake of Good , is located to the east and northeast of Esclangon . The interior of this crater has been flooded , leaving only a low rim above the surface . The rim is not quite circular , having bulges to the northeast and northwest , most likely the result of smaller craters that have merged with the main rim . The interior surface is level and nearly featureless . This formation was previously designated Macrobius L before being given a name by the IAU .