Mersenius and Gassendi

Mersenius and Gassendi are two large craters in the southwestern part of the Moon and are the next step in my quest to image the entire lunar surface.


Of the two large craters in the middle of the picture, Mersenius is on the left and Gassendi on the right. The large, smooth, dark region at the bottom of the picture is Mare Humorum and North is roughly towards one o'clock.

Mersenius is 84km in diameter, 2.3km deep and was formed nearly 4 billion years ago. The interior of the crater has been flooded by basaltic lava which has solidified into a central dome shape and covered many other features. The rim of the crater is heavily worn particularly at the northern edge. The small crater Mersenius N can be seen lying across the southwestern rim.

Gassendi is a larger and apparently shallower crater. Similarly to Mersenius, Gassendi has been filled with lava but some of the multiple central peaks are still visible. The crater situated on the northern rim is Gassendi A and the appearance of the two craters has been likened to a diamond ring.