The Moon at 22 Days Old

Mosiac of 3, 0.001 second images. SBIG ST-9E CCD with a blue filter.
16" f/10 schmidt-cassegran plus f/6.3 focal reducer.

As the Moon wanes, the sunset terminator sweeps across the lunar landscape. By the time the Moon is 22 days old, well known features such as Plato, Archimedes, and Mare Serenitatis, have all disappeared into the darkness. Even the prominent rays of Tycho are gone and the terraced walls of the crater are seeing their final glimpse of the Sun.

In the south, (top) the terminator is closing in on the large walled plain of Clavius. Closer towards the center of the Moon, the terminator is also nearing the prominent crater Copernicus, while to the north (bottom), it is swweping across Mare Imbrium, just touching the crater Timocharis. Further to the east, Sinus Iridum has several more days of daylight left.

In the above image, only the terminator region has been correctly imaged. The eastern area has saturated the CCD. In order to correctly image these brighter parts of the Moon, a neutral density filter is needed, or a longer focal length to spread the light over more pixels.