expression, noun
lunar mare; lunar sea
Astronomical term for the dark basaltic plains on the Moon's surface, formed by ancient volcanic eruptions. Often used in scientific or educational contexts.
月の海は、肉眼でも暗い模様として見える。
The lunar maria are visible to the naked eye as dark patterns.
月の海は黒っぽく見える平原です。
A lunar mare is a plain that looks dark.