Fra Mauro is the worn remnant of a walled 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...

 plain. It is part of the surrounding Fra Mauro formation

Fra Mauro formation

The Fra Mauro formation is a lunar geological formation on the near side of the Moon that served as the landing site for the American Apollo 14 mission in 1971. It is named after the 80-kilometer-diameter crater Fra Mauro, located within it...

, being located to the northeast of Mare Cognitum

Mare Cognitum

Mare Cognitum is a lunar mare located in a basin or large crater which sits in the second ring of the Procellarum basin. The basin material is of the Lower Imbrian epoch, while the basaltic mare material is of the Upper Imbrian epoch...

 and southeast of Mare Insularum

Mare Insularum

Mare Insularum is a lunar mare located in the Insularum basin just south of Mare Imbrium. The basin material is of the Lower Imbrian epoch, with the mare material of the Upper Imbrian epoch. The mare is bordered by the craters Copernicus on the east, and Kepler on the west...

. Attached to the southern rim are the co-joined craters Bonpland

Bonpland (crater)

Bonpland is the remains of a lunar crater that is attached to the walled plain Fra Mauro to the north and Parry to the east. The intersection of their rims forms a three-pointed mountainous rise. To the southeast is the small crater Tolansky...

 and Parry

Parry (crater)

Parry is a lunar crater that is attached to the southeast rim of the walled plain Fra Mauro. Attached to the west and southwest rim of Parry is the crater Bonpland. Due south of Parry is the small crater Tolansky, and farther to the south-southwest is Guericke....

, which intrude into the formation forming inward-bulging walls.

The surviving rim of Fra Mauro is heavily worn, with incisions from past impacts and openings in the north and east walls. The rim is the most prominent in the southeast, where it shares a wall with Parry. The remainder consists of little more than low, irregular ridges. The maximum elevation of the outer rim is 0.7 km.

The floor of this formation has been covered by basalt

Basalt

Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...

ic lava

Lava

Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at...

. This surface is almost divided by clefts running from the north and south rims. There is no central peak, although the tiny crater Fra Mauro E lies at almost the mid-point of the formation.

The crater was the intended landing site of the ill-fated Apollo 13

Apollo 13

Apollo 13 was the seventh manned mission in the American Apollo space program and the third intended to land on the Moon. The craft was launched on April 11, 1970, at 13:13 CST. The landing was aborted after an oxygen tank exploded two days later, crippling the service module upon which the Command...

 mission, their lunar mission was aborted after an oxygen tank aboard the spacecraft exploded. The crew later returned safely to Earth. The next lunar mission, Apollo 14

Apollo 14

Apollo 14 was the eighth manned mission in the American Apollo program, and the third to land on the Moon. It was the last of the "H missions", targeted landings with two-day stays on the Moon with two lunar EVAs, or moonwalks....

 landed at Fra Mauro.

Just to the north of the walled plain is the landing site of the Apollo 14 mission. The crew sampled breccia

Breccia

Breccia is a rock composed of broken fragments of minerals or rock cemented together by a fine-grained matrix, that can be either similar to or different from the composition of the fragments....

 that had been deposited here by the Imbrium

Mare Imbrium

Mare Imbrium, Latin for "Sea of Showers" or "Sea of Rains", is a vast lunar mare filling a basin on Earth's Moon and one of the larger craters in the Solar System. Mare Imbrium was created when lava flooded the giant crater formed when a very large object hit the Moon long ago...

basin-forming impact, and which partly covers Fra Mauro. This rough debris blanket of ejecta is referred to as the "Fra Mauro Formation".

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 Fra Mauro.

Fra Mauro	Latitude	Longitude	Diameter
A	5.4° S	20.9° W	9 km
B	4.0° S	21.7° W	7 km
C	5.4° S	21.6° W	7 km
D	4.8° S	17.6° W	5 km
E	6.0° S	16.8° W	4 km
F	6.7° S	16.9° W	3 km
G	2.2° S	16.3° W	6 km
H	4.1° S	15.5° W	6 km
J	2.6° S	18.6° W	3 km
K	2.5° S	16.7° W	6 km
N	5.3° S	17.4° W	3 km
P	5.4° S	16.5° W	3 km
R	2.2° S	15.6° W	3 km
T	2.1° S	19.3° W	3 km
W	1.3° S	16.8° W	4 km
X	4.5° S	17.3° W	20 km
Y	4.1° S	16.7° W	4 km
Z	3.8° S	14.6° W	5 km