Jenner 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...

 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 within the Mare Australe

Mare Australe

Mare Australe is a lunar mare located in the southeastern hemisphere of the Moon. It is 603 kilometers in diameter, overlapping the near and far sides of the Moon. Smooth, dark volcanic basalt lines the bottom of the mare...

. It lies just past the southeastern limb, 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...

, and can be viewed 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...

 during periods of favorable 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 lighting. Nearly attached to the eastern outer rim of Jenner is the larger, flooded crater Lamb

Lamb (crater)

Lamb is a lunar crater that lies beyond the southeastern limb on the Moon's far side. It is located in an irregular lunar mare region named Mare Australe, just to the east of the crater Jenner....

.

This is a nearly circular crater with a sharp but somewhat irregular edge that has not been significantly eroded. There are some terraces, particularly along the southwestern inner walls, and some slumping along the southeastern rim. The interior floor has been flooded 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...

, leaving a dark, level interior. There are no breaks in the exterior rim where the lava could have entered the crater, so it was presumably flooded from below. The floor is marked only by a few tiny craterlets. Surrounding Jenner is a rampart of ejecta that extends for over a half crater diameter in some directions.

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 Jenner.

Jenner	Latitude	Longitude	Diameter
M	46.0° S	95.5° E	11 km
X	37.4° S	93.7° E	13 km
Y	38.6° S	94.7° E	29 km