is a lunar crater
of sufficient dimension to belong to
the category of impact features known as walled plains. It is
located in the northeastern part of the Moon
close enough to the rim to appear significantly foreshortened.
attached to the northern rim is the crater Schumacher. To the southwest is the prominent crater
Geminus, and due
south is the smaller Bernoulli.
The outer rim of this formation has received a significant amount
of erosion due to minor impacts, but much of the outer wall retains
its original shape and a certain degree of terracing
. The rim is broken by smaller
craters along the south, north, and northwest sides, designated
Messala B, J, and K, respectively. Messala J has a narrow gouge in
its eastern rim leading one crater diameter to the east. It is
attached to a slightly larger crater which lies across the southern
rim of Schumacher.
The interior floor is relatively level but contains irregularities
in the surface at some locations. There are several small craters
across the floor, which are now little more than low rims and
depressions in the surface. The most notable of these is a ghost crater
along the western inner wall.
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 Messala.
Origin of name
is named after Masha'allah ibn Atharī
(c.740-d.815 AD), a Persian Jewish astrologer and
astronomer from the city of Basra (now located
in modern day Iraq) who was the
leading astrologer of the late 8th century.
one of the most prominent members of the commission which
determined for the Caliph al-Mansur
(A.D. 754-775) that the propitious moment for
the founding of Baghdad fell on 30