Sosigenes is a lunar

Moon

The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

 impact crater

Impact crater

In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...

 on the west edge of Mare Tranquillitatis

Mare Tranquillitatis

Mare Tranquillitatis is a lunar mare that sits within the Tranquillitatis basin on the Moon. The mare material within the basin consists of basalt formed in the intermediate to young age group of the Upper Imbrian epoch. The surrounding mountains are thought to be of the Lower Imbrian epoch, but...

. It lies to the east of the large walled plain Julius Caesar

Julius Caesar (crater)

Julius Caesar is a lava-flooded lunar crater with a low, irregular, and heavily worn wall. It is located to the west of Mare Tranquillitatis, and directly southeast of the crater Manilius on the Mare Vaporum. To the east is the rounded Sosigenes....

. The crater rim has a high albedo

Albedo

Albedo , or reflection coefficient, is the diffuse reflectivity or reflecting power of a surface. It is defined as the ratio of reflected radiation from the surface to incident radiation upon it...

, making it relatively bright. It has a small central rise at the mid-point of the floor.

To the east on the mare

Lunar mare

The lunar maria are large, dark, basaltic plains on Earth's Moon, formed by ancient volcanic eruptions. They were dubbed maria, Latin for "seas", by early astronomers who mistook them for actual seas. They are less reflective than the "highlands" as a result of their iron-rich compositions, and...

 is a formation of parallel rille

Rille

Rille is typically used to describe any of the long, narrow depressions in the lunar surface that resemble channels. Typically a rille can be up to several kilometers wide and hundreds of kilometers in length...

s designated the Rimae Sosignes. These follow a course to the north, and have a length of about 150 kilometers. The small, bowl-shaped crater Sosignes A lies across one of these rilles.

Satellite craters

By convention these features are identified on lunar maps by placing the letter on the side of the crater mid-point that is closest to Sosigenes.

Sosigenes	Latitude	Longitude	Diameter
A	7.8° N	18.5° E	12 km
B	8.3° N	17.2° E	4 km
C	7.2° N	18.9° E	3 km