The Helmet is an informal term for a highland mass within southern Oceanus Procellarum on the near side of the Moon, southeast of the crater Herigonius.
The astronauts of Apollo 16 used the term to refer to the feature during the mission.
[1] The name derives from the roughly semicircular shape of the border of the feature, resembling a helmet.
Two mountains within The Helmet are informally named Herigonius Eta (η) and Herigonius Pi (π).
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