Vendelinus is an ancient 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...

 located on the eastern 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 north of Vendelinus is the prominent crater Langrenus

Langrenus (crater)

Langrenus is a prominent impact crater located near the eastern lunar limb. The feature is circular in shape, but appears oblong due to foreshortening. It lies on the eastern shore of the Mare Fecunditatis...

, while to the southeast is Petavius

Petavius (crater)

Petavius is a large lunar impact crater located to the southeast of the Mare Fecunditatis, near the southeastern lunar limb. Attached to the northwest rim is the smaller crater Wrottesley. To the southeast are Palitzsch, Vallis Palitzsch, and Hase. Farther to the north is the large crater Vendelinus...

, forming a chain of prominent craters near the eastern rim. Due to its location, the crater appears oblong due to foreshortening.

The crater is heavily worn and overlapped by multiple craters, making this feature more difficult to identify except at low sun angles. The irregular rim is broken in several locations by overlapping craters. The most prominent of these is the break in the northeast wall from the overlapping crater Lamé

Lamé (crater)

Lamé is a lunar impact crater located astride the northeast rim of the crater Langrenus, to the east of Mare Fecunditatis. The eastern crater rim appears overlaid by a series of overlapping craters that form an intermittent chain flowing nearly a hundred kilometers to the south...

. The smaller Lohse

Lohse (lunar crater)

Lohse is a lunar crater on the eastern edge of Mare Fecunditatis. It is attached to the north rim of the larger crater Vendelinus. To the north is the prominent Langrenus. The interior of Lohse is rough, with a notable central peak. An older impact is attached to the north rim, designated Langrenus...

 overlaps the rim to the northwest, and at the south end the crater wall is joined to Holden

Holden (lunar crater)

Holden is a lunar crater attached to the southeast rim of the much larger crater Vendelinus. The crater rim is impacted by a craterlet on the north-northwest, and it possesses a terrace along the northeast interior wall. The floor of the crater is flat with no central peak. There is a small crater...

.

The floor of Vendelinus is flat and covered by a dark 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...

 flow. (Webb

Thomas William Webb

The Reverend Thomas William Webb was a British astronomer. Some sources give his year of birth as 1806. The only son of a clergyman, the Rev. John Webb, he was raised and educated by his father, his mother having died while Thomas was a small child. He went to Oxford where he attended Magdalen...

 noted that a dark patch could be seen on the floor of this crater at full moon

Full moon

Full moon lunar phase that occurs when the Moon is on the opposite side of the Earth from the Sun. More precisely, a full moon occurs when the geocentric apparent longitudes of the Sun and Moon differ by 180 degrees; the Moon is then in opposition with the Sun.Lunar eclipses can only occur at...

.) It lacks a central peak, but includes multiple impact craters of various dimensions. Some of these are secondary craters from Langrenus

Langrenus (crater)

Langrenus is a prominent impact crater located near the eastern lunar limb. The feature is circular in shape, but appears oblong due to foreshortening. It lies on the eastern shore of the Mare Fecunditatis...

, and display an oblong shape. The outer ramparts of Lamé form a rise on the northeastern floor.

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 Vendelinus.

Vendelinus	Latitude	Longitude	Diameter
D	19.0° S	58.2° E	10 km
E	17.9° S	61.0° E	21 km
F	18.5° S	65.0° E	32 km
H	15.3° S	61.4° E	7 km
K	13.8° S	62.5° E	9 km
L	17.6° S	61.7° E	17 km
N	16.8° S	65.9° E	18 km
P	17.6° S	66.3° E	16 km
S	15.4° S	57.9° E	5 km
T	13.5° S	62.8° E	5 km
U	16.0° S	58.7° E	5 km
V	15.5° S	55.8° E	5 km
W	14.6° S	58.7° E	5 km
Y	17.5° S	62.2° E	10 km
Z	17.2° S	62.3° E	7 km

The following craters have been renamed by the IAU

International Astronomical Union

The International Astronomical Union IAU is a collection of professional astronomers, at the Ph.D. level and beyond, active in professional research and education in astronomy...

:

• Vendelinus C — See Lamé (crater)
  Lamé (crater)
  Lamé is a lunar impact crater located astride the northeast rim of the crater Langrenus, to the east of Mare Fecunditatis. The eastern crater rim appears overlaid by a series of overlapping craters that form an intermittent chain flowing nearly a hundred kilometers to the south...
  
  .