DictionarymareDark planetary plain
noun

mare

A large dark plain on the Moon or Mars.

The telescope reveals a broad dark mare on the Moon.

Etymology

Latin mare means sea. Early lunar observers applied the name to dark plains that looked like seas, and the geographical label remained after their true nature was understood.

More examples

  • Several maria were visible near the lunar equator.
  • The map labels each prominent mare.
  • Ancient lava filled the basin that became this mare.

Forms

mare · maria