Peek 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...

 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...

 that is located in the northern part 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...

 near the eastern limb 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...

. This part of the lunar surface is subject to the effects of 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:...

, and the crater can be hidden from sight during an unfavorable libration. Even when visible, however, the crater is seen almost edge-on, making it difficult to see much detail from the 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...

. Due to foreshortening the crater appears close to Schubert

Schubert (lunar crater)

Schubert is a lunar impact crater that lies near the eastern limb of the Moon's near side. The crater is located to the northwest of the Mare Smythii, and southwest of the prominent crater Neper...

, even though the two are about 60 km apart. It lies to the south-southeast of the large crater Neper

Neper (crater)

Neper is an old lunar impact crater located near the eastern limb of the Moon. Due to its location the crater must be viewed during a suitable libration, and is very foreshortened. The crater lies on the south edge of Mare Marginis, to the east of the crater Jansky...

.

This crater is generally circular and bowl-shaped, with a small interior floor at the center of the sloping inner walls. The crater has a higher 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...

 than the surrounding dark lunar 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...

, making it appear slightly brighter than the nearby terrain. The crater has not been significantly eroded by subsequent impacts.