Twelve Day Old Moon‡

The Waxing Gibbous Moon will be visible during the late afternoon and is visible all night setting in early morning near dawn. It transits near midnight, which makes for a night of good observing. Moon Filters are especially useful, as the increasing glare from the Moon's disk becomes more overwhelming.


Key Features to Observe Tonight

The medium-sized crater Mairan in the tumbled bright highlands southwest of Sinus Iridium is outstanding tonight. Aristarchus, about midway to the equator, not far from the terminator, also continues to grow brighter and increase in prominence. South of it, the crater Marius comes into view tonight.

Northwest of Mare Humorum, near the terminator in bright highlands beyond the dark mare, stands a distinctive pair of craters, similar in size and depth, but contrasting markedly in albedo: Billy, and northwest of it by about its diameter, Hansteen. Billy's floor is smooth and one of the darkest parts of the face of the Moon, while Hansteen has a rough, bright floor.

Midway from the equator to the south pole, along the terminator, is the eye-catching walled plain Schickard. It has a convex floor, dark at both the north and south ends.

Further south is a double crater resembling an impression left by a giant's shoe! The northwestern "heel" is Nasmyth, while the larger southeastern crater, the "sole" is Phocylides.

West of Nasmyth is Wargentin, one of the most unusual objects on the Moon. Lava has welled up from inside it but was completely contained by its unbroken rim wall. The result is a smooth, flat-topped disc, a round plateau of a crater above the surrounding surface.

Of course the ring mountain crater Tycho, to the west of the center of the southern hemisphere, dominates the lunar disc with its brilliant ray system tonight.


‡with permission from Lunar Discoverer User's Manual by Robert Duvall, 2013