twelve-thirteen day moon |
Class 1 ring mountain Tycho, to the west of the centre of the southern hemisphere, dominates the lunar disc with its brilliant ray system.
Far to its north-west, near the terminator and in the region where the bright southern landscape joins the dark Maria to the north, stands a distinctive pair: Billy, and just beyond it, at a distance about equal to its diameter, Hansteen. Both are class 5, about 30 miles across and some 4000' deep, but they contrast markedly - whilst Hansteen has a rough, bright floor, Billy's is smooth and one of the darkest parts of the face of the Moon.
Two Humorum lengths south along the terminator is the conspicuous walled plain Schickard. It is class 5, and its convex floor is dark at both the north and south ends. Its curvature is so strong it would prevent its walls from being seen from its centre.
Slightly further south is a double crater resembling the impression left by a gigantic shoe! The north-western "heel" is the ancient Nasmyth, while the larger south-eastern component (roughly twice the size) is class 3 Phocylides.
Adjacent to Nasmyth on the west is class 5 Wargentin, one of the weirdest objects on the Moon. At some point in its history, lava welled up from inside it and was contained by its even and unbroken walls. Then, just before it reached the rim, the flow stopped and the lava set. The result is a smooth, flat-topped disc, which has been nicknamed "The Thin Cheese" due to its resemblance to a huge camembert!