Hirayama is a large 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...

 that is located on the far side of the Moon

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...

, just beyond the eastern limb. This region of the surface is sometimes brought into view from Earth

Earth

Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

 during periods of favourable libration

Libration

In astronomy, libration is an oscillating motion of orbiting bodies relative to each other, notably including the motion of the Moon relative to Earth, or of Trojan asteroids relative to planets.-Lunar libration:...

. However it is best viewed from orbit

Orbit

In physics, an orbit is the gravitationally curved path of an object around a point in space, for example the orbit of a planet around the center of a star system, such as the Solar System...

. This crater is located along the southeastern edge of the Mare Smythii

Mare Smythii

Mare Smythii is a lunar mare located along the equator on the easternmost edge of the lunar near side. The Smythii basin where the mare is located is of the Pre-Nectarian epoch, while the surrounding features are of the Nectarian system...

, to the northeast of the crater Brunner

Brunner (crater)

Brunner is a lunar impact crater that is located along the eastern limb of the Moon, to the southeast of the Mare Smythii. At this location the crater is viewed from the edge, and so it is not possible to see much detail from the Earth. The visibility of this formation is also affected by libration...

. To the northeast of Hirayama is Wyld

Wyld (crater)

Wyld is a lunar impact crater that is located on the Moon's far side, beyond the eastern limb. It lies in that portion of the lunar surface that is sometimes brought into view of the Earth under conditions of favorable libration and illumination, but even then the crater is seen from the edge and...

.

This is a worn and eroded crater with multiple impacts overlapping the outer rim and the interior floor. Hirayama K has broken across the rim to the southeast and Hirayama C crosses the northeastern rim. Along the southwestern outer edge is Hirayama Q. The small Hirayama T is located along the western inner wall, and attached to its eastern edge is Hirayama S. The crater Hirayama Y is adjacent to the northern inner walls of Hirayama and covers a significant part of the northern interior floor. Several smaller craters lie within the floor, including Hirayama N in the south. The floor otherwise forms a relatively level surface within the inner wall.

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 Hirayama.

Hirayama	Latitude	Longitude	Diameter
C	4.2° S	95.4° E	23 km
F	5.8° S	97.2° E	35 km
G	6.4° S	96.8° E	18 km
K	8.3° S	94.9° E	39 km
L	9.4° S	94.4° E	24 km
M	9.2° S	93.5° E	29 km
N	7.2° S	93.6° E	17 km
Q	8.0° S	91.3° E	40 km
S	6.5° S	92.3° E	29 km
T	6.4° S	91.5° E	18 km
Y	4.5° S	93.2° E	50 km