Lunar mare

The Lunar maria (singular: mare) are large, dark, basaltic plains on Earth's Moon, formed by ancient basaltic flood eruptions caused by extremely large meteoroid impacts. They were dubbed maria, Latin for "seas", by early astronomers who mistook them for actual seas.

The Lunar Maria

Latin Name	English Name	Lat	Long	Diameter (km)
Mare Anguis	Serpent Sea	22.6N	67.7E	150
Mare Australe	Southern Sea	38.9S	93.0E	603
Mare Cognitum	Sea that has become known	10.0S	23.1W	376
Mare Crisium	Sea of Crises	17.0N	59.1E	418
Mare Fecunditatis	Sea of Fecundity	7.8S	51.3E	909
Mare Frigoris	Sea of Cold	56.0N	1.4E	1596
Mare Humboldtianum	Sea of Alexander von Humboldt	56.8N	81.5E	273
Mare Humorum	Sea of Moisture	24.4S	38.6W	389
Mare Imbrium	Sea of Showers	32.8N	15.6W	1123
Mare Ingenii	Sea of Cleverness	33.7S	163.5E	318
Mare Insularum	Sea of Islands	7.5N	30.9W	513
Mare Marginis	Sea of the Edge	13.3N	86.1E	420
Mare Moscoviense	Sea of Muscovy	27.3N	147.9E	277
Mare Nectaris	Sea of Nectar	15.2S	35.5E	333
Mare Nubium	Sea of Clouds	21.3S	16.6W	715
Mare Orientale	Eastern sea	19.4S	92.8W	327
Mare Serenitatis	Sea of Serenity	28.0N	17.5E	707
Mare Smythii	Sea of William Henry Smyth	1.3N	87.5E	373
Mare Spumans	Foaming Sea	1.1N	65.1E	139
Mare Tranquillitatis	Sea of Tranquility	8.5N	31.4E	873
Mare Undarum	Sea of Waves	6.8N	68.4E	243
Mare Vaporum	Sea of Vapors	13.3N	3.6E	245
Oceanus Procellarum	Ocean of Storms	18.4N	57.4W	2568

A related set of features are the Lunar lacus, Latin for "lake", which are smaller basaltic plains of similar origin:

Lunar laci

Latin Name	English Name	Lat	Long	Diameter (km)
Lacus Aestatis[?]	Lake of Summer	15.0S	69.0W	90
Lacus Autumni[?]	Lake of Autumn	9.9S	83.9W	183
Lacus Bonitatis[?]	Lake of Goodness	23.2N	43.7E	92
Lacus Doloris[?]	Lake of Sorrow	17.1N	9.0E	110
Lacus Excellentiae[?]	Lake of Excellence	35.4S	44.0W	184
Lacus Felicitatis[?]	Lake of Happiness	19.0N	5.0E	90
Lacus Gaudii[?]	Lake of Joy	16.2N	12.6E	113
Lacus Hiemalis[?]	Wintry Lake	15.0N	14.0E	50
Lacus Lenitatis[?]	Lake of Softness	14.0N	12.0E	80
Lacus Luxuriae[?]	Lake of Luxury	19.0N	176.0E	50
Lacus Mortis[?]	Lake of Death	45.0N	27.2E	151
Lacus Oblivionis[?]	Lake of Forgetfulness	21.0S	168.0W	50
Lacus Odii[?]	Lake of Hatred	19.0N	7.0E	70
Lacus Perseverantiae[?]	Lake of Perseverance	8.0N	62.0E	70
Lacus Solitudinis[?]	Lake of Solitude	27.8S	104.3E	139
Lacus Somniorum[?]	Lake of Dreams	38.0N	29.2E	384
Lacus Spei[?]	Lake of Hope	43.0N	65.0E	80
Lacus Temporis[?]	Lake of Time	45.9N	58.4E	117
Lacus Timoris[?]	Lake of Fear	38.8S	27.3W	117
Lacus Veris[?]	Lake of Spring	16.5S	86.1W	396