Mare Serenitatis is virtually a circular formation measuring approximately 650 km in diameter in all directions and covers an area of slightly over 300,000 square km. It is one of the smoothest mare, for the mare floor is characterized with its largest crater, Bessel, whose diameter only reaches 16 km. Inspection of the image below indicates the presence of approximately ten very small and normally hard-to-detect craterlets whose diameter is each well below 7 km. The greatest characteristic features of Mare Serenitatis are perhaps the circular and walled plain formation Posidonius (95 km in diameter) on the northeast periphery and Dorsa Smirnov immediately to the west of Posidonius running north-south (130 km in length, 20 km in width). The southern periphery of Mare Serenitatis includes the 16-km in diameter crater Plinius whose rays leading into Mare Serenitatis suggest an impact of some type. Various ridges of interest but not visible in the image below include Dorsa Owen and Buckland to the west and Nicol and Lister to the south. The ridge immediately to the west of the imaginary line joining the landing sites for Apollo 17 and Luna 21 is Dorsa Aldovandri, a ridge measuring 120 km in length and 10 km in diameter.

Note: The landing of the Apollo 17 lunar module in the Taurus-Littrow area on December 11, 1972, regrettably, marked the final manned mission to the lunar surface. This particular mission involved the collection of 110 kg of lunar samples over the course of 21 hours by Cernan and Schmidt using the Lunar Rover. Approximately two months later, the Soviet probe Luna 21 soft-landed slightly further north on January 15, 1973 where an automated and mobile laboratory ranged nearly 40 km from the landing site performing various experiments. A complete enumeration of all landing sites for Apollo, Luna and Surveyor craft is available elsewhere on this site.

Note: The reimaging of Mare Serenitatis with more favourable colour and contrast will be attempted during the forthcoming lunations.