Combination of 20, 0.02 second exposures.
SBIG ST8XE CCD. 20" f/6.8 Dall-Kirkham cassegrain telescope with a 2x barlow lens.
A little to the East of the crater Plato, located in the Lunar Alps, is a deep gorge known as the Alpine Valley. It is readily visible when the Moon is close to first or third quarter.
