Bullialdus is a lunarimpact crater located in the western part of the Mare Nubium. It was named after French astronomer Ismaël Boulliau.[1] To the north by north-west is the broken-rimmed and lava-flooded crater Lubiniezky. South-west of Bullialdus lies the smaller crater König.
Another Oblique view from Apollo 16
The relatively isolated location of this crater serves to highlight its well-formed shape. Bullialdus has a high outer rim that is circular but observers have noted a slightly polygonal appearance. The inner walls are terraced and contain many signs of landslips. The outer ramparts are covered in a wide ejecta blanket that highlights a radial pattern of low ridges and valleys.
Bullialdus crater as viewed from earth, below left of center
In the center of the crater is a formation of several peaks and rises that climb to over a kilometer in height. A raised ridge runs from the peaks to the south-east, until finally merging with the inner wall. The floor of the crater is generally rough with many low rises. Overall it has a somewhat convex shape, bulging upward toward the middle. When the Sun is at a high angle, the rim and central mountains appear brighter than the surroundings, and white patches can be viewed on the crater floor.
Infrared studies of the crater region have revealed at least three layers of strata. The impact may also have intersected a maficpluton, which means a crystallized body of igneous rock that has high concentrations of heavier elements (such as magnesium, in this case).
By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Bullialdus. Bullialdus A lies just to the south-west of Bullialdus, within its ramparts. To the south of Bullialdus A is the slightly smaller Bullialdus B.
Bullialdus
Latitude
Longitude
Diameter
A
22.1° S
21.5° W
26 km
B
23.4° S
21.9° W
21 km
E
21.7° S
23.9° W
4 km
F
22.5° S
24.8° W
6 km
G
23.2° S
23.6° W
4 km
H
22.7° S
19.3° W
5 km
K
21.8° S
25.6° W
12 km
L
20.2° S
24.4° W
4 km
R
20.1° S
19.8° W
17 km
Y
18.5° S
19.1° W
4 km
References
^"Bullialdus (crater)". Gazetteer of Planetary Nomenclature. USGS Astrogeology Research Program.
S. Tompkins et al., "Distribution and geologic history of materials excavated by the lunar crater Bullialdus", Twenty-Fourth Lunar and Planetary Science Conference, Part 3, 1993.
Andersson, L. E.; Whitaker, E. A. (1982). NASA Catalogue of Lunar Nomenclature. NASA RP-1097.
Menzel, D. H.; Minnaert, M.; Levin, B.; Dollfus, A.; Bell, B. (1971). "Report on Lunar Nomenclature by the Working Group of Commission 17 of the IAU". Space Science Reviews. 12 (2): 136–186. Bibcode:1971SSRv...12..136M. doi:10.1007/BF00171763. S2CID122125855.
Wood, Chuck (May 3, 2004). "Bully for Bullialdus". Lunar Photo of the Day. Archived from the original on May 30, 2018. Retrieved November 12, 2017.
Wood, Chuck (August 23, 2004). "Almost on the Ground". Lunar Photo of the Day. Archived from the original on May 30, 2018. Retrieved November 12, 2017.
