Bullialdus (crater)
Encyclopedia
Bullialdus is a lunar
impact crater
located in the western part of the Mare Nubium
. To the north by north-west is the broken-rimmed and lava-flooded crater Lubiniezky
. South-west of Bullialdus lies the smaller crater König
.
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.
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 mafic
pluton
, which means a crystal
lized body of igneous rock
that has high concentrations of heavier elements (such as magnesium
, in this case).
Two smaller but notable craters lie just to the south of the main crater. 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.
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 in the western part of the Mare Nubium
Mare Nubium
Mare Nubium is a lunar mare in the Nubium basin on the Moon's near side. The mare is located just to the southeast of Oceanus Procellarum. The actual basin is believed to be of Pre-Nectarian system, with the surrounding basin material being of the Lower Imbrian epoch. The mare material is of the...
. To the north by north-west is the broken-rimmed and lava-flooded crater Lubiniezky
Lubiniezky (crater)
Lubiniezky is a lava-flooded lunar crater on the northwest edge of Mare Nubium. This feature is most readily located by finding the prominent crater Bullialdus to the southeast....
. South-west of Bullialdus lies the smaller crater König
König (crater)
König is a lunar crater on the southwest Mare Nubium. It lies to the southwest of the prominent crater Bullialdus, and northwest of the flooded Kies. The rim of König is somewhat polygonal in outline, with a small outward bulge to the south and only a slight outer rampart. The crater interior is...
.
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.
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
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
studies of the crater region have revealed at least three layers of strata. The impact may also have intersected a mafic
Mafic
Mafic is an adjective describing a silicate mineral or rock that is rich in magnesium and iron; the term is a portmanteau of the words "magnesium" and "ferric". Most mafic minerals are dark in color and the relative density is greater than 3. Common rock-forming mafic minerals include olivine,...
pluton
Intrusion
An intrusion is liquid rock that forms under Earth's surface. Magma from under the surface is slowly pushed up from deep within the earth into any cracks or spaces it can find, sometimes pushing existing country rock out of the way, a process that can take millions of years. As the rock slowly...
, which means a crystal
Crystal
A crystal or crystalline solid is a solid material whose constituent atoms, molecules, or ions are arranged in an orderly repeating pattern extending in all three spatial dimensions. The scientific study of crystals and crystal formation is known as crystallography...
lized body of igneous rock
Igneous rock
Igneous rock is one of the three main rock types, the others being sedimentary and metamorphic rock. Igneous rock is formed through the cooling and solidification of magma or lava...
that has high concentrations of heavier elements (such as magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
, in this case).
Two smaller but notable craters lie just to the south of the main crater. 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.
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 Bullialdus.| 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 |