 | |
| Coordinates | 88°06′S44°54′E / 88.1°S 44.9°E |
|---|---|
| Diameter | 50.9 km |
| Depth | 2.5 Km |
| Colongitude | 342° at sunrise |
| Eponym | Eugene Shoemaker |
Shoemaker is a lunar impact crater located near the southern pole of the Moon, within half a crater diameter of Shackleton.
It lies to the south of the crater Malapert, to the east of Haworth, and just to the west of the similar-sized Faustini. The rim of Shoemaker is circular and worn, with some small craters along the inner wall. Due to the lack of illumination (it is a crater of eternal darkness), the albedo of the interior floor surface remains unknown.
Prior to being given its current name by the IAU, this formation had been informally named Mawson (after the Antarctic explorer Douglas Mawson). It was officially named Shoemaker in honor of Eugene Shoemaker, the geologist whose remains were on board the Lunar Prospector spacecraft that impacted this crater floor. Deposition of Shoemaker's remains was criticized by indigenous peoples as a desecration of the venerated Moon. [1]
This crater became of interest to scientists when the Lunar Prospector detected unusually high concentrations of hydrogen on the floor of this and other nearby craters using a neutron spectrometer. The floor of this crater is kept in permanent shadow from the Sun, and thus maintains a temperature below 100 K (−173 °C). Thus the floor forms a cold trap, and any molecules of water that wander into the crater from cometary impacts can deposit on the floor and remain there almost permanently. The instruments on board Lunar Prospector gave a concentration of about 146 ppm of hydrogen, compared to 50 ppm for the average lunar surface.
The topography of this crater was subsequently measured using the Goldstone 70 m antenna to irradiate it with 3.5 cm radar. Two 34 m antennae, located 20 km apart, received the echoes, and the results were used to generate a topographic map with 150 m resolution. [2]
On July 31, 1999, Lunar Prospector was deliberately crashed into the floor of this crater to determine if a plume of water vapor would be detected. The apparent detection of water and the shallow rim of this crater made it a suitable target for this experiment. However the outcome was unsuccessful. Subsequent tests have failed to confirm the presence of water in the crater floor, so the hydrogen found in the crater bottom is likely to prove more difficult to extract than had been originally hoped.
Alder is a lunar impact crater that is located in the southern hemisphere on the far side of the Moon. It is located in the South Pole-Aitken basin, and lies to the southeast of the crater Von Kármán. Southeast of Alder is Bose, and to the south-southwest lies Boyle.
Hermite is a lunar impact crater located along the northern lunar limb, close to the north pole of the Moon. Named for Charles Hermite, the crater was formed roughly 3.91 billion years ago.
Ångström is a small lunar impact crater located on the border between Oceanus Procellarum to the west and Mare Imbrium to the east. To the south is a formation of mountains rising out of the mare named the Montes Harbinger. To the east are some wrinkle ridges named the Dorsum Bucher and Dorsa Argand. This crater is bowl-shaped, with a circular rim and inner walls that slope down to the small central floor. It has a higher albedo than the surrounding maria. The crater halo is radar dark, indicating a lack of larger blocks among the fine ejecta.
Aitken is a large lunar impact crater that lies on the far side of the Moon, named for Robert Grant Aitken, an American astronomer specializing in binary stellar systems. It is located to the southeast of the crater Heaviside, and north of the unusual formation Van de Graaff. Attached to the southwest rim is Vertregt. To the southeast is the smaller Bergstrand.
Clavius is one of the largest crater formations on the Moon and the second largest crater on the visible near side. It is located in the rugged southern highlands of the Moon, to the south of the prominent ray crater Tycho. It is named for the Jesuit priest Christopher Clavius.
Bessel is a small lunar impact crater that is located in the southern half of the Mare Serenitatis. The crater was named after the German astronomer Friedrich Wilhelm Bessel in 1935. Despite its small size, this is the largest crater to lie entirely within the mare. It lies to the north-northeast of the crater Menelaus.
Shackleton is an impact crater that lies at the lunar south pole. The peaks along the crater's rim are exposed to almost continual sunlight, while the interior is perpetually in shadow. The low-temperature interior of this crater functions as a cold trap that may capture and freeze volatiles shed during comet impacts on the Moon. Measurements by the Lunar Prospector spacecraft showed higher than normal amounts of hydrogen within the crater, which may indicate the presence of water ice. The crater is named after Antarctic explorer Ernest Shackleton.
Ashbrook is a large lunar impact crater that is located in the vicinity of the south pole on the far side of the Moon, and so cannot be viewed directly from the Earth. The eastern face of the crater has been overlain by the similar-sized Drygalski, and more than half the interior floor of Ashbrook is covered by the outer ramparts and ejecta of Drygalski. To the northwest is the walled plain Zeeman.
Cabeus is a lunar impact crater that is located about 100 km (62 mi) from the south pole of the Moon. At this location the crater is seen obliquely from Earth, and it is almost perpetually in deep shadow due to lack of sunlight. Hence, not much detail can be seen of this crater, even from orbit. Through a telescope, this crater appears near the southern limb of the Moon, to the west of the crater Malapert and to the south-southwest of Newton.
de Gerlache is a lunar impact crater that is located along the southern limb of the Moon, within a crater diameter of Shackleton at the south pole. From the Earth this crater is seen from the edge, and it lies in perpetual darkness. Thus little or no detail can be seen of this crater, other than the edge of the rim. However, the crater is clearly visible in Earth-based radar images. The crater is roughly circular, with some slight wear. No craters of note overlie the rim, although some formations may be attached to the southern and western edges.
De Forest is a lunar impact crater on the far side of the Moon. It is located in the far southern hemisphere, to the west of the large walled plain Zeeman and due south of the crater Numerov. Because of its proximity to the southern pole, this crater receives sunlight at an oblique angle when it is on the illuminated half of the Moon.
Bondarenko is a lunar impact crater on the far side of the Moon. It is located to the northeast of the large, dark-floored crater Tsiolkovskiy, and south of the crater Chauvenet. This is a worn crater formation with an irregular floor, similar to other craters in the area, which are covered by ejecta from Tsiolkovskiy.
Faustini is a lunar impact crater that lies near the south pole of the Moon. It is located nearly due south of the much larger crater Amundsen, and is almost attached to Shoemaker to the southwest. About one crater diameter due south is the smaller crater Shackleton at the south pole. A small crater is attached to the eastern rim of Faustini.
Malapert is a lunar impact crater that lies near the southern limb of the Moon. From the Earth this formation is viewed from the side, limiting the amount of detail that can be seen. The crater is also illuminated at very low angles, so that parts of the interior remain in almost constant darkness. The nearest craters of note are Cabeus to the west, and Shoemaker to the south-southeast and nearer to the south pole of the Moon.
Lunar water is water that is present on the Moon. Diffuse water molecules in low concentrations can persist at the Moon's sunlit surface, as discovered by the SOFIA observatory in 2020. Gradually, water vapor is decomposed by sunlight, leaving hydrogen and oxygen lost to outer space. Scientists have found water ice in the cold, permanently shadowed craters at the Moon's poles. Water molecules are also present in the extremely thin lunar atmosphere.
Nobile is a lunar impact crater that is located near the southern pole of the Moon. It was named after the Italian aviator and explorer Umberto Nobile by the International Astronomical Union (IAU) in 1994. It lies to the south of the crater Scott, along the western rim of Amundsen. Between Nobile and the southern pole lie the smaller craters Shoemaker and Faustini.
Fibiger is a lunar impact crater located on the lunar near side near the northern pole. The nearest major feature is the Byrd crater. The crater was adopted and named after Danish pathologist Johannes Andreas Grib Fibiger in 2009 by the IAU. Located just north of Fibiger are craters Erlanger and Peary, which are 9.9 km and 73 km in diameter, respectively.
Whipple is a lunar impact crater located on the lunar far side near the northern pole. The crater is located East of the prominent craters Byrd and Peary; the latter of which it is located on the rim of.
Cai Lun is a lunar impact crater located on the lunar far side near the northern pole. The crater is located in between the prominent craters Haskin and Nansen. Cai Lun was adopted and named after Chinese inventor Cai Lun by the IAU in August, 2010.
Slater is an impact crater near the south pole of the Moon. Like nearby Shackleton, the floor of the crater is in nearly perpetual darkness.
