Located on the eastern Oceanus Procellarum it is estimated to be 800 million years old. The remarkable details in the walls are an indication of its geologic youth and hence lack of erosion. The crater diameter is 58 miles and depth 12,500 feet.
Below is Gassendi- around 68 miles across and over 6000 feet deep
‘Gassendi A’ is the small ‘diamond in the ring’ intruding into the northern rim. The crater is on the nortern edge of Mare Humorum. Here is a nice lunar map reference
Both images captured on New Year’s Eve 2006 with a waxing gibbous moon.
