Gruithuisen 32.9°N, 39.7°W

Gruituisen is a small crater of 16 km in diameter and a depth of about 1.9 km, lying at the northern end of Dorsum Bucher. It was probably formed during the Eratosthenian period on the lunar timescale.

The crater was named after Franz von Paula Gruithuisen (1774–1852), professor of astronomy and lunar observer, who, however, after publications about the ‘Discovery of many clear traces of inhabitants on the Moon and a colossal artificial structure of theirs’ exposed himself to ridicule, because it had been known for a long time that there is neither air nor water on the Moon.

The crater Gruithuisen is a classic example of a simple crater, according to the USGS standard sequence for lunar craters.

Mairan 41.6°N, 43.4°W

Mairan is a relatively young crater, 40 km in diameter, with a sharply defined crater wall and a slightly eccentrically placed, small central peak. Mairan T, with a diameter of only 3 km is a volcanic dome with a summit crater, lying west of Mairan. The rille Rima Mairan (38.0°N, 47.0°W) lies south of Mairan T. It is a linear rille, with a maximum width of 2 km, that runs for an overall length of 90 km. Directly northwest of Mairan lies the almost completely destroyed crater Louville, with a diameter of about 36 km and the two craterlets Louville A and B (both about 8 km across). Louville is difficult to locate in its extemely craggy surroundings.