<Tr> <Td> Vallis Schröteri </Td> <Td> 26 ° 12 ′ N 50 ° 48 ′ W ﻿ / ﻿ 26.2 ° N 50.8 ° W ﻿ / 26.2; - 50.8 </Td> <Td> 168 km </Td> <Td> Johann Hieronymus Schröter </Td> <Td> Schröter </Td> </Tr> <Tr> <Td> Vallis Snellius </Td> <Td> 31 ° 06 ′ S 56 ° 00 ′ E ﻿ / ﻿ 31.1 ° S 56.0 ° E ﻿ / - 31.1; 56.0 </Td> <Td> 592 km </Td> <Td> Willebrord Snell </Td> <Td> Snellius </Td> </Tr> <P> This is a list of maria (singular mare) on the Moon . Lunar Maria are the large, dark, regions of the moon . They do not actually contain any water, however they are believed to have been formed from molten rock from the moon's mantle coming out onto the surface of the moon . It also includes the one oceanus and the features known by the names lacus, palus and sinus . The modern system of lunar nomenclature was introduced in 1651 by Riccioli . Riccioli's map of the moon was drawn by Francesco Maria Grimaldi, who has a crater named after him . </P> <Table> Lunar Maria <Tr> <Th> Latin Name </Th> <Th> English Name </Th> <Th> Lat . </Th> <Th> Long . </Th> <Th> Diameter </Th> </Tr> <Tr> <Td> Mare Anguis </Td> <Td> Serpent Sea </Td> <Td> 22.6 ° N </Td> <Td> 67.7 ° E </Td> <Td> 150 km </Td> </Tr> <Tr> <Td> Mare Australe </Td> <Td> Southern Sea </Td> <Td> 38.9 ° S </Td> <Td> 93.0 ° E </Td> <Td> 603 km </Td> </Tr> <Tr> <Td> Mare Cognitum </Td> <Td> Sea that has become known </Td> <Td> 10.0 ° S </Td> <Td> 23.1 ° W </Td> <Td> 376 km </Td> </Tr> <Tr> <Td> Mare Crisium </Td> <Td> Sea of Crisis </Td> <Td> 17.0 ° N </Td> <Td> 59.1 ° E </Td> <Td> 555 km </Td> </Tr> <Tr> <Td> Mare Fecunditatis </Td> <Td> Sea of Fecundity </Td> <Td> 7.8 ° S </Td> <Td> 51.3 ° E </Td> <Td> 909 km </Td> </Tr> <Tr> <Td> Mare Frigoris </Td> <Td> Sea of Cold </Td> <Td> 56.0 ° N </Td> <Td> 1.4 ° E </Td> <Td> 1596 km </Td> </Tr> <Tr> <Td> Mare Humboldtianum </Td> <Td> Sea of Alexander von Humboldt </Td> <Td> 56.8 ° N </Td> <Td> 81.5 ° E </Td> <Td> 273 km </Td> </Tr> <Tr> <Td> Mare Humorum </Td> <Td> Sea of Moisture </Td> <Td> 24.4 ° S </Td> <Td> 38.6 ° W </Td> <Td> 389 km </Td> </Tr> <Tr> <Td> Mare Imbrium </Td> <Td> Sea of Showers </Td> <Td> 32.8 ° N </Td> <Td> 15.6 ° W </Td> <Td> 1123 km </Td> </Tr> <Tr> <Td> Mare Ingenii </Td> <Td> Sea of Cleverness </Td> <Td> 33.7 ° S </Td> <Td> 163.5 ° E </Td> <Td> 318 km </Td> </Tr> <Tr> <Td> Mare Insularum </Td> <Td> Sea of Islands </Td> <Td> 7.5 ° N </Td> <Td> 30.9 ° W </Td> <Td> 513 km </Td> </Tr> <Tr> <Td> Mare Marginis </Td> <Td> Sea of the Edge </Td> <Td> 13.3 ° N </Td> <Td> 86.1 ° E </Td> <Td> 420 km </Td> </Tr> <Tr> <Td> Mare Moscoviense </Td> <Td> Sea of Muscovy </Td> <Td> 27.3 ° N </Td> <Td> 147.9 ° E </Td> <Td> 277 km </Td> </Tr> <Tr> <Td> Mare Nectaris </Td> <Td> Sea of Nectar </Td> <Td> 15.2 ° S </Td> <Td> 35.5 ° E </Td> <Td> 333 km </Td> </Tr> <Tr> <Td> Mare Nubium </Td> <Td> Sea of Clouds </Td> <Td> 21.3 ° S </Td> <Td> 16.6 ° W </Td> <Td> 715 km </Td> </Tr> <Tr> <Td> Mare Orientale </Td> <Td> Eastern Sea </Td> <Td> 19.4 ° S </Td> <Td> 92.8 ° W </Td> <Td> 327 km </Td> </Tr> <Tr> <Td> Mare Serenitatis </Td> <Td> Sea of Serenity </Td> <Td> 28.0 ° N </Td> <Td> 17.5 ° E </Td> <Td> 707 km </Td> </Tr> <Tr> <Td> Mare Smythii </Td> <Td> Sea of William Henry Smyth </Td> <Td> 1.3 ° N </Td> <Td> 87.5 ° E </Td> <Td> 373 km </Td> </Tr> <Tr> <Td> Mare Spumans </Td> <Td> Foaming Sea </Td> <Td> 1.1 ° N </Td> <Td> 65.1 ° E </Td> <Td> 139 km </Td> </Tr> <Tr> <Td> Mare Tranquillitatis </Td> <Td> Sea of Tranquility </Td> <Td> 8.5 ° N </Td> <Td> 31.4 ° E </Td> <Td> 873 km </Td> </Tr> <Tr> <Td> Mare Undarum </Td> <Td> Sea of Waves </Td> <Td> 6.8 ° N </Td> <Td> 68.4 ° E </Td> <Td> 243 km </Td> </Tr> <Tr> <Td> Mare Vaporum </Td> <Td> Sea of Vapors </Td> <Td> 13.3 ° N </Td> <Td> 3.6 ° E </Td> <Td> 245 km </Td> </Tr> <Tr> <Td> Oceanus Procellarum </Td> <Td> Ocean of Storms </Td> <Td> 18.4 ° N </Td> <Td> 57.4 ° W </Td> <Td> 2568 km </Td> </Tr> </Table>

What is the name for the dark spots on the moon