Gerard (crater)
Encyclopedia
Gerard is a lunar
crater
that lies along the western edge of the Oceanus Procellarum
near the northwest limb of the Moon
's near side. It is located to the north-northwest of the crater von Braun
, and northeast of Bunsen
. Because of its location, Gerard appears strongly foreshortened when viewed from the Earth
, hindering observation.
This is a worn and eroded formation with a rim that has been nearly obliterated in some locations and distorted in others. The northern half of the rim has outward bulges to the northeast, north, and northwest. The interior floor is rough in places, with several small and tiny craters along the floor and the eastern rim. Attached to the northwest rim is the satellite crater Gerard Q, a formation that has its eastern floor covered in dark-hue
d basalt
ic lava
.
To the northwest of this formation and Gerard Q is a system of rille
s named the Rimae Gerard. These extend for a distance of about 100 kilometers.
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...
that lies along the western edge of the Oceanus Procellarum
Oceanus Procellarum
Oceanus Procellarum is a vast lunar mare on the western edge of the near side of the Earth's Moon. Its name derives from the old superstition that its appearance during the second quarter heralded bad weather...
near the northwest limb 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...
's near side. It is located to the north-northwest of the crater von Braun
Von Braun (crater)
von Braun, named after the rocket pioneer Wernher von Braun, is a lunar crater located near the northwestern limb of the Moon. It lies along the western edge of the Oceanus Procellarum, to the northeast of the crater Lavoisier. The northeastern rim of this crater is on the edge of the Sinus Roris,...
, and northeast of Bunsen
Bunsen (crater)
Bunsen is a lunar crater that lies near the northwestern limb of the Moon. It is located to the west of the Oceanus Procellarum and the crater von Braun. To the southeast is the crater Lavoisier, and to the northeast lies Gerard. Northwest of Bunsen, on the far side of the Moon, is McLaughlin...
. Because of its location, Gerard appears strongly foreshortened when viewed from the Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
, hindering observation.
This is a worn and eroded formation with a rim that has been nearly obliterated in some locations and distorted in others. The northern half of the rim has outward bulges to the northeast, north, and northwest. The interior floor is rough in places, with several small and tiny craters along the floor and the eastern rim. Attached to the northwest rim is the satellite crater Gerard Q, a formation that has its eastern floor covered in dark-hue
Hue
Hue is one of the main properties of a color, defined technically , as "the degree to which a stimulus can be describedas similar to or different from stimuli that are described as red, green, blue, and yellow,"...
d basalt
Basalt
Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...
ic 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...
.
To the northwest of this formation and Gerard Q is a system of rille
Rille
Rille is typically used to describe any of the long, narrow depressions in the lunar surface that resemble channels. Typically a rille can be up to several kilometers wide and hundreds of kilometers in length...
s named the Rimae Gerard. These extend for a distance of about 100 kilometers.
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 Gerard.| Gerard | Latitude | Longitude | Diameter |
|---|---|---|---|
| A | 45.1° N | 82.3° W | 17 km |
| B | 46.4° N | 88.3° W | 14 km |
| C | 45.9° N | 79.2° W | 27 km |
| D | 46.2° N | 79.9° W | 5 km |
| E | 44.5° N | 81.0° W | 5 km |
| F | 43.8° N | 82.3° W | 5 km |
| G | 45.7° N | 88.3° W | 22 km |
| H | 44.5° N | 87.0° W | 13 km |
| J | 46.9° N | 88.7° W | 10 km |
| K | 44.0° N | 77.2° W | 7 km |
| L | 43.2° N | 76.4° W | 4 km |
| Q | 46.6° N | 83.1° W | 7 km |