Secchi is a small 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...

 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...

 formation on the northwest edge of Mare Fecunditatis

Mare Fecunditatis

Mare Fecunditatis is a lunar mare which is 840 km in diameter. The Fecuditatis basin formed in the Pre-Nectarian epoch, while the basin material surrounding the mare is of the...

. To the northeast is the crater Taruntius

Taruntius (crater)

Taruntius is a lunar crater on the northwestern edge of Mare Fecunditatis. To the northwest is the lava-flooded crater Lawrence, and to the north lie the craters Watts and da Vinci...

. The western rim is joined with a section of the minor Montes Secchi

Montes Secchi

Montes Secchi is minor range of lunar mountains that located near the northwestern edge of Mare Fecunditatis. This roughly linear formation of low ridges grazes the northwestern outer rim of the crater Secchi, the formation from which this range gained its name...

 range. The rim of this crater has been opened in the northern and southern ends, leaving two curved ridges facing each other across the crater floor. To the south is a pair of 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 Secchi. These lie near the edge of 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...

, and have a combined length of about 40 kilometers.

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 Secchi.

Secchi	Latitude	Longitude	Diameter
A	3.3° N	41.5° E	5 km
B	3.7° N	41.5° E	5 km
G	4.0° N	44.6° E	8 km
K	0.2° S	45.4° E	3 km
U	1.1° N	42.2° E	6 km
X	0.7° S	43.6° E	6 km