Messala (crater)
Encyclopedia
Messala 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. Nearly 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.
and astronomer
from the city of Basra
(now located in modern day Iraq
) who was the leading astrologer of the late 8th century. Masha'allah was 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 July 762
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...
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
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...
, close enough to the rim to appear significantly foreshortened. Nearly attached to the northern rim is the crater Schumacher
Schumacher (crater)
Schumacher is a lunar crater that lies in the northeast part of the Moon, just to the north of the larger walled plain Messala. The two formations are separated by a rough strip of terrain less than 10 kilometers across, and bisected by a pair of small, co-joined craters...
. To the southwest is the prominent crater Geminus
Geminus (crater)
Geminus is a lunar impact crater that is located near the northeast limb of the visible Moon. In this position the crater appears oval in shape due to foreshortening, but it is actually more nearly circular in form...
, and due south is the smaller Bernoulli
Bernoulli (crater)
Bernoulli is a lunar impact crater that is located in the northeast part of the Moon. It lies to the south of the crater Messala, and east of Geminus....
.
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
Palimpsest
A palimpsest is a manuscript page from a scroll or book from which the text has been scraped off and which can be used again. The word "palimpsest" comes through Latin palimpsēstus from Ancient Greek παλίμψηστος originally compounded from πάλιν and ψάω literally meaning “scraped...
along the western 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 Messala.Origin of name
The crater is named after Masha'allah ibn Atharī (c.740-d.815 AD), a Persian Jewish astrologerAstrologer
An astrologer practices one or more forms of astrology. Typically an astrologer draws a horoscope for the time of an event, such as a person's birth, and interprets celestial points and their placements at the time of the event to better understand someone, determine the auspiciousness of an...
and astronomer
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
from the city of Basra
Basra
Basra is the capital of Basra Governorate, in southern Iraq near Kuwait and Iran. It had an estimated population of two million as of 2009...
(now located in modern day Iraq
Iraq
Iraq ; officially the Republic of Iraq is a country in Western Asia spanning most of the northwestern end of the Zagros mountain range, the eastern part of the Syrian Desert and the northern part of the Arabian Desert....
) who was the leading astrologer of the late 8th century. Masha'allah was one of the most prominent members of the commission which determined for the Caliph
Caliph
The Caliph is the head of state in a Caliphate, and the title for the ruler of the Islamic Ummah, an Islamic community ruled by the Shari'ah. It is a transcribed version of the Arabic word which means "successor" or "representative"...
al-Mansur
Al-Mansur
Al-Mansur, Almanzor or Abu Ja'far Abdallah ibn Muhammad al-Mansur was the second Abbasid Caliph from 136 AH to 158 AH .-Biography:...
(A.D. 754-775) that the propitious moment for the founding of Baghdad
Baghdad
Baghdad is the capital of Iraq, as well as the coterminous Baghdad Governorate. The population of Baghdad in 2011 is approximately 7,216,040...
fell on 30 July 762
| Messala | Latitude | Longitude | Diameter |
|---|---|---|---|
| A | 36.6° N | 53.8° E | 26 km |
| B | 37.4° N | 59.9° E | 18 km |
| C | 40.9° N | 65.8° E | 12 km |
| D | 40.5° N | 67.8° E | 28 km |
| E | 40.0° N | 64.9° E | 40 km |
| F | 38.9° N | 64.4° E | 32 km |
| G | 39.1° N | 68.6° E | 29 km |
| J | 41.1° N | 61.2° E | 15 km |
| K | 41.1° N | 58.5° E | 13 km |