Glossary term: Mare

Also known as Maria

Description: A mare, from the Latin for "sea", is one of a series of dark flat areas on the Moon made of basalt. These are thought to be the result of ancient volcanic eruptions that left behind a relatively smooth landscape compared to the light, older, jagged lunar highlands. Their name comes from their similar appearance to flat, watery seas. We now know that these areas are very dry with no surface water.

The Mare Tranquillitatis (Sea of Tranquility) was the site of the landing of Apollo 11, the first crewed mission to touch down on the Moon.

Related Terms:

See this term in other languages

Term and definition status: This term and its definition have been approved by a research astronomer and a teacher

The OAE Multilingual Glossary is a project of the IAU Office of Astronomy for Education (OAE) in collaboration with the IAU Office of Astronomy Outreach (OAO). The terms and definitions were chosen, written and reviewed by a collective effort from the OAE, the OAE Centers and Nodes, the OAE National Astronomy Education Coordinators (NAECs) and other volunteers. You can find a full list of credits here. All glossary terms and their definitions are released under a Creative Commons CC BY-4.0 license and should be credited to "IAU OAE".