Diameter 350 km | ||
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Eponym Sea That Has Become Known, or Known Sea | ||
Mare Cognitum ("The Sea that has Become Known") is a lunar mare located in a basin or large crater which sits in the second ring of Oceanus Procellarum. To the northwest of the mare is the Montes Riphaeus mountain range, part of the rim of the buried crater or basin containing the mare. Previously unnamed, the mare received its name in 1964 in reference to its selection as the target for the successful impact probe Ranger 7, the first American spacecraft to return close up images of the Moon's surface.
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Origin
The basin material is of the Lower Imbrian epoch, while the basaltic mare material is of the Upper Imbrian epoch.
Exploration
The Ranger 7 lunar probe impacted Mare Cognitum at the conclusion of its picture-taking mission. Surveyor 3 and Apollo 12 landed near its northern shore. The outcrop of the Fra Mauro formation, where Apollo 14 landed, is also located near Mare Cognitum.