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Langrenus (crater)
Encyclopedia
Langrenus is a prominent impact crater
located near the eastern lunar
limb. The feature is circular in shape, but appears oblong due to foreshortening. It lies on the eastern shore of the Mare Fecunditatis
. To the south is the overlapping crater pair Vendelinus
and the smaller Lamé
.
The inner wall of Langrenus is wide and irregularly terraced, with an average width of about 20 kilometers. The outer ramparts are irregular and hilly, and there is a bright, fragmented ray system
spread across the mare to the west. The interior of the crater has a higher albedo
than the surroundings, so the crater stands out prominently when the Sun
is overhead. The crater floor is covered by many boulder
s, and is slightly irregular in the northwest half. The central peaks rise about a kilometer above the floor, and a peak on the eastern rim ascends to an altitude of 3 km.
During the Apollo 8
mission, Astronaut
James Lovell
described Langrenus as "quite a huge crater; it's got a central cone to it. The walls of the crater are terraced, about six or seven terraces on the way down."
In the past this crater has not been noted as a site for observing transient lunar phenomena
. However on December 30, 1992, Audouin Dollfus of the Observatoire de Paris
observed a series of glows on the floor of this crater using the one-meter telescope
. These glows changed form with time, and Professor Dollfus expressed the belief that this was likely a gaseous emission. The cracked floor of the crater may have been the source of the gas.
The Flemish Astronomer Michel Florent van Langren was the first person to draw a lunar map while giving names to many of the features. He even named this crater after himself. Ironically, this is the only one of his named features that has retained his original designation.
Many of the more significant associated craters that surround Langrenus have since been renamed by the IAU
.
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 near the eastern lunar
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...
limb. The feature is circular in shape, but appears oblong due to foreshortening. It lies on the eastern shore of the Mare Fecunditatis
Mare Fecunditatis
Mare Fecunditatis is a lunar mare which is 840 km in diameter. The Fecuditatis basin formed in the Pre-Nectarian epoch, while the basin material surrounding the mare is of the...
. To the south is the overlapping crater pair Vendelinus
Vendelinus (crater)
Vendelinus is an ancient lunar impact crater located on the eastern edge of Mare Fecunditatis. To the north of Vendelinus is the prominent crater Langrenus, while to the southeast is Petavius, forming a chain of prominent craters near the eastern rim...
and the smaller Lamé
Lamé (crater)
Lamé is a lunar impact crater located astride the northeast rim of the crater Langrenus, to the east of Mare Fecunditatis. The eastern crater rim appears overlaid by a series of overlapping craters that form an intermittent chain flowing nearly a hundred kilometers to the south...
.
The inner wall of Langrenus is wide and irregularly terraced, with an average width of about 20 kilometers. The outer ramparts are irregular and hilly, and there is a bright, fragmented ray system
Ray system
A ray system comprises radial streaks of fine ejecta thrown out during the formation of an impact crater, looking a bit like many thin spokes coming from the hub of a wheel. The rays can extend for lengths up to several times the diameter of their originating crater, and are often accompanied by...
spread across the mare to the west. The interior of the crater has a higher albedo
Albedo
Albedo , or reflection coefficient, is the diffuse reflectivity or reflecting power of a surface. It is defined as the ratio of reflected radiation from the surface to incident radiation upon it...
than the surroundings, so the crater stands out prominently when the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
is overhead. The crater floor is covered by many boulder
Boulder
In geology, a boulder is a rock with grain size of usually no less than 256 mm diameter. While a boulder may be small enough to move or roll manually, others are extremely massive....
s, and is slightly irregular in the northwest half. The central peaks rise about a kilometer above the floor, and a peak on the eastern rim ascends to an altitude of 3 km.
During the Apollo 8
Apollo 8
Apollo 8, the second manned mission in the American Apollo space program, was the first human spaceflight to leave Earth orbit; the first to be captured by and escape from the gravitational field of another celestial body; and the first crewed voyage to return to Earth from another celestial...
mission, Astronaut
Astronaut
An astronaut or cosmonaut is a person trained by a human spaceflight program to command, pilot, or serve as a crew member of a spacecraft....
James Lovell
Jim Lovell
James "Jim" Arthur Lovell, Jr., is a former NASA astronaut and a retired captain in the United States Navy, most famous as the commander of the Apollo 13 mission, which suffered a critical failure en route to the Moon but was brought back safely to Earth by the efforts of the crew and mission...
described Langrenus as "quite a huge crater; it's got a central cone to it. The walls of the crater are terraced, about six or seven terraces on the way down."
In the past this crater has not been noted as a site for observing transient lunar phenomena
Transient lunar phenomenon
A transient lunar phenomenon , or lunar transient phenomenon , is a short-lived light, color, or change in appearance on the lunar surface....
. However on December 30, 1992, Audouin Dollfus of the Observatoire de Paris
Paris Observatory
The Paris Observatory is the foremost astronomical observatory of France, and one of the largest astronomical centres in the world...
observed a series of glows on the floor of this crater using the one-meter telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...
. These glows changed form with time, and Professor Dollfus expressed the belief that this was likely a gaseous emission. The cracked floor of the crater may have been the source of the gas.
The Flemish Astronomer Michel Florent van Langren was the first person to draw a lunar map while giving names to many of the features. He even named this crater after himself. Ironically, this is the only one of his named features that has retained his original designation.
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 Langrenus.| Albategnius | Latitude | Longitude | Diameter |
|---|---|---|---|
| E | 12.7° S | 60.6° E | 30 km |
| G | 12.1° S | 65.4° E | 23 km |
| H | 8.0° S | 64.3° E | 23 km |
| L | 13.2° S | 62.2° E | 12 km |
| M | 9.8° S | 66.4° E | 17 km |
| N | 9.0° S | 65.7° E | 12 km |
| P | 12.1° S | 63.1° E | 42 km |
| Q | 11.9° S | 60.7° E | 12 km |
| R | 7.7° S | 63.6° E | 5 km |
| S | 6.7° S | 64.7° E | 9 km |
| T | 4.6° S | 62.5° E | 42 km |
| U | 12.6° S | 57.1° E | 4 km |
| V | 13.2° S | 55.9° E | 5 km |
| W | 8.6° S | 67.3° E | 23 km |
| X | 12.4° S | 64.7° E | 25 km |
| Y | 7.8° S | 66.9° E | 27 km |
| Z | 7.1° S | 66.4° E | 20 km |
Many of the more significant associated craters that surround Langrenus have since been renamed by the IAU
International Astronomical Union
The International Astronomical Union IAU is a collection of professional astronomers, at the Ph.D. level and beyond, active in professional research and education in astronomy...
.
- Langrenus A — See BarklaBarkla (crater)Barkla is a lunar impact crater that lies near the eastern limb of the Moon. It is located to the east of the prominent crater Langrenus, and was formerly designated Langrenus A before being renamed by the IAU. Due east of Barkla is Kapteyn, a formation only slightly larger with a similar size...
. - Langrenus B — See NaonobuNaonobu (crater)Naonobu is a small lunar impact crater named after Japanese mathematician Ajima Naonobu. It is located on the eastern Mare Fecunditatis, to the northwest of the prominent crater Langrenus, and it forms a triple-crater formation with the adjacent Atwood to the south and Bilharz just to the southwest...
. - Langrenus C — See Acosta craterAcosta (crater)Acosta is a small lunar impact crater located just to the north of the prominent crater Langrenus, near the east edge of Mare Fecunditatis. To the west are the trio of Atwood, Naonobu, and Bilharz. Acosta is named after the Portuguese natural historian Cristóbal Acosta.The crater is circular and...
. - Langrenus D — See Al-MarrakushiAl-Marrakushi (crater)Al-Marrakushi is a small, relatively isolated lunar impact crater in the eastern Mare Fecunditatis. It is a circular, symmetrical formation, with inner walls that slope down to the mid-point. To the northeast is the prominent crater Langrenus...
. - Langrenus F — See BilharzBilharz (crater)Bilharz is a lunar impact crater that lies in the eastern part of the Mare Fecunditatis. It is the largest member of a close triple-crater formation with Atwood to the east and Naonobu to the northeast. To the southeast is the prominent crater Langrenus....
. - Langrenus J — See SomervilleSomerville (crater)Somerville is a small lunar crater in the eastern part of the Moon. It lies to the east of the prominent crater Langrenus, and was designated Langrenus J before being given a name by the IAU. This is a roughly circular, bowl-shaped formation, with the larger but less conspicuous Langrenus H...
. - Langrenus K — See AtwoodAtwood (crater)Atwood is a small lunar impact crater that is located on the Mare Fecunditatis, to the northwest of the prominent crater Langrenus. It forms a triple-crater formation with Naonobu attached to the north rim and Bilharz near the west rim. All three were satellite craters of Langrenus before being...
.