Twenty-Seven Day Old Moon‡

The Moon is now a thin crescent. It will only be visible for a short while before sunrise, hanging low in the eastern sky. Observing is difficult, as it is close to the new Moon. Any obstructions on the horizon, such as trees, may hamper seeing before sunrise.

The slender crescent is difficult to view. Contrast is generally low, features muted. There is little area to observe left, with the New Moon fast approaching.

 

Key Features to Observe Tonight

The slender crescent is difficult to view. Contrast is generally low, features muted. There is little area to observe left, with the New Moon fast approaching.

Near the northern cusp, the walled plain Pythagoras is one of the few significant features left to view, showing fair contrast between shadow and highlight, but difficult to see due to its proximity to the limb and foreshortening. Favorable librations will help.

In the southern hemisphere, under favorable libration, the Cordillera Mountains may be seen near the limb about a quarter of the way down from the equator. They represent the outer ring wall of Mare Orientale, a farside lunar feature which is only occasionally glimpsed under uncommon libration.

The large walled plain Schickard tonight appears as a low smooth hollow on the terminator, having lost much of its earlier detail in the low light. Between Schickard and the limb lies Inghirami, greatly foreshortened. Midway to the southern cusp is another huge walled plain, Bailly, considered the largest nearside crater, which almost now engulfs the entire thin crescent at the southern cusp.

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