Rimae Secchi

Rimae Secchi is a system of rilles on the Moon, in northwestern Mare Fecunditatis.

[1] In 1974, the name Fossae Secchi was proposed on a map[2] published by the US Defense Mapping Agency, but this name was not adopted (on the Moon, the term Rima is traditionally used instead of Fossa).

[3] The northern end of Rimae Secchi is Y-shaped, and the southern part consists of several separate troughs.

The northern part of Rimae Secchi is surrounded with a dark halo, probably pyroclastic deposits like volcanic ash.

Such deposits are common near the edges of lunar maria, including several areas in Mare Fecunditatis.

Northeastern portion of Rimae Secchi. Photo by Apollo 11 , 1969.
Ghost crater with Rimae Secchi atop its northwestern rim. A smaller ghost crater is seen inside the bigger one. Photo by LRO , 2018.