Bailly (crater)
Encyclopedia
Bailly is a lunar
impact crater
that is located near the south-west limb of the Moon
. The oblique viewing angle gives the crater a foreshortened appearance, and the location near the limb can limit visibility due to libration
. The most favorable time for viewing this feature is near the full moon
when the terminator
is crossing the crater wall.
This is the largest crater on the near side of the Moon. In area it is comparable in size to a small mare. It lies north of the crater Le Gentil
and east of Hausen
. Further west of Bailly are the (unofficially named) Montes Dörfel mountains.
Bailly's uneven crater floor has remained free of lava
flooding, and it is covered with a multitude of ridges and craters. The entire crater has been battered and worn, and the outer ramparts are eroded and in some places have even been worn away by myriad impacts. If the crater ever possessed a central peak, it is no longer discernible. Due to its current condition, observers have termed this feature a 'field of ruins'.
The south-eastern part of the crater is home to two notable craters, designated Bailly A and Bailly B. These craters overlap, and Bailly A lies across the rim of Bailly's mountainous wall.
Due to the size and the worn state of this crater, it is estimated to be more than 3 billion years old.
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...
that is located near the south-west 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...
. The oblique viewing angle gives the crater a foreshortened appearance, and the location near the limb can limit visibility due to libration
Libration
In astronomy, libration is an oscillating motion of orbiting bodies relative to each other, notably including the motion of the Moon relative to Earth, or of Trojan asteroids relative to planets.-Lunar libration:...
. The most favorable time for viewing this feature is near the full moon
Full moon
Full moon lunar phase that occurs when the Moon is on the opposite side of the Earth from the Sun. More precisely, a full moon occurs when the geocentric apparent longitudes of the Sun and Moon differ by 180 degrees; the Moon is then in opposition with the Sun.Lunar eclipses can only occur at...
when the terminator
Terminator (solar)
A terminator, twilight zone or "grey line" is a moving line that separates the illuminated day side and the dark night side of a planetary body...
is crossing the crater wall.
This is the largest crater on the near side of the Moon. In area it is comparable in size to a small mare. It lies north of the crater Le Gentil
Le Gentil (crater)
Le Gentil is a lunar crater that is located in the south-southwest part of the Moon, near the limb, and is nearly attached to the southern rim of the huge walled plain Bailly. To the southeast is the large crater Drygalski...
and east of Hausen
Hausen (crater)
Hausen is a large lunar impact crater that lies along the south-southwestern limb of the Moon. The visibility of this crater is significantly affected by libration effects, although even under the best of conditions it is viewed nearly from on edge. It lies along the western edge of the immense...
. Further west of Bailly are the (unofficially named) Montes Dörfel mountains.
Bailly's uneven crater floor has remained free of 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...
flooding, and it is covered with a multitude of ridges and craters. The entire crater has been battered and worn, and the outer ramparts are eroded and in some places have even been worn away by myriad impacts. If the crater ever possessed a central peak, it is no longer discernible. Due to its current condition, observers have termed this feature a 'field of ruins'.
The south-eastern part of the crater is home to two notable craters, designated Bailly A and Bailly B. These craters overlap, and Bailly A lies across the rim of Bailly's mountainous wall.
Due to the size and the worn state of this crater, it is estimated to be more than 3 billion years old.
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 Bailly.| Bailly | Latitude | Longitude | Diameter |
|---|---|---|---|
| A | 69.3° S | 59.5° W | 38 km |
| B | 68.8° S | 63.1° W | 65 km |
| C | 65.6° S | 69.6° W | 20 km |
| D | 65.2° S | 72.2° W | 23 km |
| E | 62.5° S | 65.7° W | 13 km |
| F | 67.5° S | 69.2° W | 16 km |
| G | 65.6° S | 59.1° W | 18 km |
| H | 63.5° S | 62.1° W | 12 km |
| K | 62.8° S | 76.5° W | 20 km |
| L | 60.8° S | 70.9° W | 20 km |
| M | 61.4° S | 68.4° W | 23 km |
| N | 60.5° S | 63.6° W | 11 km |
| O | 69.6° S | 56.7° W | 16 km |
| P | 59.6° S | 60.6° W | 15 km |
| R | 64.8° S | 80.0° W | 18 km |
| T | 66.5° S | 72.8° W | 18 km |
| U | 71.3° S | 75.8° W | 20 km |
| V | 72.0° S | 85.0° W | 29 km |
| Y | 61.3° S | 66.6° W | 12 km |
| Z | 60.2° S | 65.6° W | 12 km |