Object: L 44
Feature Name: Mersenius
Significance: Domed floor cut by secondary craters

The rim of Mersenius is heavily worn, especially in the low northern section. The crater Mersenius N lies across the southwestern rim. The interior has been flooded by basaltic lava, which bulges upwards forming a convex domed shape with an estimated height of 450 metres relative to the floor edges. This was most likely formed by lava upwelling beneath the surface. There are several tiny craterlets across the floor surface, but little in the way of a central peak. At least two faint rilles lie along the surface of the floor.

To the east of the crater on the surface and edges of the Mare Humorum is a rille system designated Rimae Mersenius. These rilles are generally parallel and run to the north-northeast for a length of about 230 kilometers.

DMK 21AU-4.AS through 200mm f/4 GSO Newtonian with Tele Vue 5x Powermate.

Best of 2500 frames stacked in Registax. Processed in Astra Image 3.0, Nebulosity and Paintshop Pro.