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Shackleton (crater)
Encyclopedia
Shackleton is an impact crater
that lies at the south pole
of the Moon
. 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 Ernest Shackleton
, a noted Anglo-Irish
explorer of the Antarctic
.
on a massif
. The rim is slightly raised about the surrounding surface and it has an outer rampart that has been only lightly impacted. No significant craters intersect the rim, and it is sloped about 1.5° toward the direction 50–90° from the Earth. The age of the crater is about 3.6 billion years and it has been in the proximity of the south lunar pole for at least the last two billion years.
Because the orbit of the Moon is tilted only 5° from the ecliptic
, the interior of this crater lies in perpetual darkness. Peaks along the rim of the crater are almost continually illuminated by sunlight, spending about 80–90% of each lunar orbit exposed to the Sun
. Continuously illuminated mountains have been termed peaks of eternal light
and have been predicted to exist since the 1900s.
The shadowed portion of the crater was imaged with the Terrain Camera of the Japan
ese SELENE
spacecraft using the illumination of sunlight reflected off the rim. The interior of the crater consists of a symmetrical 30° slope that leads down to a 6.6 km diameter floor. The handful of craters along the interior span no more than a few hundred meters. The bottom is covered by an uneven mound-like feature that is 300 to 400 m thick. The central peak is about 200 m in height.
The continuous shadows in the south polar craters cause the floors of these formations to maintain a temperature that never exceeds about 100 K. For Shackleton, the average temperature was determined to be about 90 K, reaching 88 K at the crater floor. Under these conditions, the estimated rate of loss from any ice in the interior would be 10−26 to 10−27 m/s. Any water vapor that arrives here following a comet
ary impact on the Moon would lie permanently frozen on or below the surface. However, the surface albedo
of the crater floor matches the lunar far-side, suggesting that there is no exposed surface ice.
This crater was named after Ernest Henry Shackleton, an Anglo-Irish
explorer of Antarctica from 1901 until his death in 1922. The name was officially adopted by the International Astronomical Union
in 1994. Nearby craters of note include Shoemaker
, Haworth
, de Gerlache
, Sverdrup
, and Faustini
. Somewhat farther away, on the eastern hemisphere of the lunar near side, are the larger craters Amundsen
and Scott
, named after two other early explorers of the Antarctic
continent.
, this crater lies along the southern limb of the Moon, making observation difficult. Detailed mapping of the polar regions and farside of the Moon did not occur until the advent of orbiting spacecraft. Shackleton lies entirely within the rim of the immense South Pole-Aitken basin
, which is one of the largest known impact formations in the Solar System
. This basin is over 12 kilometers deep, and an exploration of its properties could provide useful information about the lunar interior.
A neutron
spectrometer
on board the Lunar Prospector
spacecraft detected enhanced concentrations of hydrogen
close to the northern and southern lunar poles, including the crater Shackleton. At the end of this mission in July 1999, the spacecraft was crashed into the nearby crater Shoemaker
in the hope of detecting from Earth-based telescopes an impact-generated plume containing water vapor. The impact event did not produce any detectable water vapor, and this may be an indication that the hydrogen is not in the form of hydrate
d mineral
s, or that the impact site did not contain any ice. Alternatively, it is possible that the crash did not excavate deeply enough into the regolith
to liberate significant quantities of water vapor.
From images of the crater edge taken from orbit, Shackleton appears to be relatively intact; much like a young crater that has not been significantly eroded from subsequent impacts. This may mean that the inner sides are relatively steep, which may make traversing the sides relatively difficult for a robotic vehicle. In addition, it is possible that the interior floor might not have collected a significant quantity of volatiles since its formation. However other craters in the vicinity are considerably older, and may contain significant deposits of hydrogen
, possibly in the form of water ice. (See Shoemaker (lunar crater)
, for example.)
Radar
studies following the Lunar Prospector mission demonstrate that the inner walls of Shackleton are similar in reflective characteristics
to those of some sunlit craters. In particular, the surroundings appear to contain a significant number of blocks in its ejecta blanket, suggesting that its radar properties are a result of surface roughness, and not ice deposits, as was previously suggested from a radar experiment involving the Clementine mission
. This interpretation, however, is not universally agreed upon within the scientific community. Radar images of the crater at a wavelength of 13 cm show no evidence for water ice deposits.
Optical imaging inside the crater was done for the first time by the Japanese lunar orbiter spacecraft Kaguya
in 2007. It did not have any evidence of significant amount of water ice, down to the image resolution of 10 m per pixel.
On November 15, 2008, a 34-kg probe made a hard landing near the crater. The moon impact probe (MIP) was launched from the Indian Chandrayaan-I spacecraft and reached the surface 25 minutes later. The probe carried a radar altimeter, video imaging system, and a mass spectrometer, which will be used to search for water.
using solar panel
s, potentially making them good locations for future Moon landing
s. The temperature at this site is also more favorable than at more equatorial latitudes as it does not experience the daily temperature extremes of 100 °C when the Sun is overhead, to as low as −150 °C during the lunar night.
While scientific experiments performed by Clementine
and Lunar Prospector
could indicate the presence of water in the polar craters, the current evidence is far from definitive. There are doubts among scientists as to whether or not the hydrogen is in the form of ice, as well as to the concentration of this "ore" with depth below the surface. Resolution of this issue will require future missions to the Moon. The presence of water suggests that the crater floor could potentially be "mined" for deposits of hydrogen
in water form, a commodity that is expensive to deliver directly from the Earth.
This crater has also been proposed as a future site for a large infrared
telescope
. The low temperature of the crater floor makes it ideal for infrared observations, and solar cell
s placed along the rim could provide near-continuous power to the observatory. About 120 kilometers from the crater lies the 5-km tall Malapert Mountain, a peak that is perpetually visible from the Earth
, and which could serve as a radio
relay station when suitably equipped.
NASA
has named the rim of Shackleton as a potential candidate for its lunar outpost
, slated to be up and running by 2020 and continuously staffed by a crew by 2024. The location would promote self-sustainability for lunar residents, as perpetual sunlight on the south pole would provide energy for solar panels. Furthermore, the shadowed polar regions are believed to contain the frozen water necessary for human consumption and could also be harvested for fuel manufacture.
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 at the south pole
Lunar south pole
The lunar south pole is of special interest to scientists because of the postulated occurrence of ice in permanently shadowed areas. Of the lunar poles, the south pole is of greater interest because the area that remains in shadow is much larger than that at the north pole. The lunar south pole...
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 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
Volatiles
In planetary science, volatiles are that group of chemical elements and chemical compounds with low boiling points that are associated with a planet's or moon's crust and/or atmosphere. Examples include nitrogen, water, carbon dioxide, ammonia, hydrogen, and methane, all compounds of C, H, O...
shed during comet
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...
impacts on the Moon. Measurements by the Lunar Prospector
Lunar Prospector
The Lunar Prospector mission was the third selected by NASA for full development and construction as part of the Discovery Program. At a cost of $62.8 million, the 19-month mission was designed for a low polar orbit investigation of the Moon, including mapping of surface composition and possible...
spacecraft showed higher than normal amounts of hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
within the crater, which may indicate the presence of water ice. The crater is named after Ernest Shackleton
Ernest Shackleton
Sir Ernest Henry Shackleton, CVO, OBE was a notable explorer from County Kildare, Ireland, who was one of the principal figures of the period known as the Heroic Age of Antarctic Exploration...
, a noted Anglo-Irish
Anglo-Irish
Anglo-Irish was a term used primarily in the 19th and early 20th centuries to identify a privileged social class in Ireland, whose members were the descendants and successors of the Protestant Ascendancy, mostly belonging to the Church of Ireland, which was the established church of Ireland until...
explorer of the Antarctic
Antarctic
The Antarctic is the region around the Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica and the ice shelves, waters and island territories in the Southern Ocean situated south of the Antarctic Convergence...
.
Description
The rotational axis of the Moon lies within Shackleton, only a few kilometers from its center. The crater is 21 km in diameter and 4.2 km deep. From the Earth, it is viewed edge-on in a region of rough, cratered terrain. It is located within the South Pole-Aitken basinSouth Pole-Aitken basin
The South Pole-Aitken basin is an impact crater on Earth's Moon. Roughly in diameter and deep, it is one of the largest known impact craters in the Solar System. It is the largest, oldest and deepest basin recognized on the Moon. This moon basin was named for two features on opposing sides; the...
on a massif
Massif
In geology, a massif is a section of a planet's crust that is demarcated by faults or flexures. In the movement of the crust, a massif tends to retain its internal structure while being displaced as a whole...
. The rim is slightly raised about the surrounding surface and it has an outer rampart that has been only lightly impacted. No significant craters intersect the rim, and it is sloped about 1.5° toward the direction 50–90° from the Earth. The age of the crater is about 3.6 billion years and it has been in the proximity of the south lunar pole for at least the last two billion years.
Because the orbit of the Moon is tilted only 5° from the ecliptic
Ecliptic
The ecliptic is the plane of the earth's orbit around the sun. In more accurate terms, it is the intersection of the celestial sphere with the ecliptic plane, which is the geometric plane containing the mean orbit of the Earth around the Sun...
, the interior of this crater lies in perpetual darkness. Peaks along the rim of the crater are almost continually illuminated by sunlight, spending about 80–90% of each lunar orbit exposed to 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...
. Continuously illuminated mountains have been termed peaks of eternal light
Peak of Eternal Light
Peak of Eternal Light describes a point on a body within the Solar System which is eternally bathed in sunlight. This is due to both the bodies' rotation and the point's altitude...
and have been predicted to exist since the 1900s.
The shadowed portion of the crater was imaged with the Terrain Camera of the Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
ese SELENE
SELENE
SELENE , better known in Japan by its nickname after the legendary Japanese moon princess, was the second Japanese lunar orbiter spacecraft. Produced by the Institute of Space and Astronautical Science and the National Space Development Agency , both now part of the Japan Aerospace Exploration...
spacecraft using the illumination of sunlight reflected off the rim. The interior of the crater consists of a symmetrical 30° slope that leads down to a 6.6 km diameter floor. The handful of craters along the interior span no more than a few hundred meters. The bottom is covered by an uneven mound-like feature that is 300 to 400 m thick. The central peak is about 200 m in height.
The continuous shadows in the south polar craters cause the floors of these formations to maintain a temperature that never exceeds about 100 K. For Shackleton, the average temperature was determined to be about 90 K, reaching 88 K at the crater floor. Under these conditions, the estimated rate of loss from any ice in the interior would be 10−26 to 10−27 m/s. Any water vapor that arrives here following a comet
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...
ary impact on the Moon would lie permanently frozen on or below the surface. However, the surface 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...
of the crater floor matches the lunar far-side, suggesting that there is no exposed surface ice.
This crater was named after Ernest Henry Shackleton, an Anglo-Irish
Anglo-Irish
Anglo-Irish was a term used primarily in the 19th and early 20th centuries to identify a privileged social class in Ireland, whose members were the descendants and successors of the Protestant Ascendancy, mostly belonging to the Church of Ireland, which was the established church of Ireland until...
explorer of Antarctica from 1901 until his death in 1922. The name was officially adopted by the International Astronomical Union
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...
in 1994. Nearby craters of note include Shoemaker
Shoemaker (lunar crater)
Shoemaker is a lunar crater that is 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...
, Haworth
Haworth (crater)
Haworth is an impact crater that lies at the south pole of the Moon. The crater is named after Walter Haworth.-Description:The crater was imaged by Diviner. Cabeus Crater is nearby.-External links:*...
, de Gerlache
De Gerlache (crater)
de Gerlache is a lunar 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...
, Sverdrup
Sverdrup (crater)
Sverdrup is a lunar crater that is located about one crater diameter from the southern pole of the Moon. It lies on the far side of the Moon with respect to the Earth, in an area of the surface that is only illuminated by very oblique light from the Sun. The interior part of the crater is cloaked...
, and Faustini
Faustini (crater)
Faustini is a lunar 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...
. Somewhat farther away, on the eastern hemisphere of the lunar near side, are the larger craters Amundsen
Amundsen (crater)
Amundsen is a large lunar impact crater located near the south pole of the Moon, named after the Norwegian explorer Roald Amundsen. It lies along the southern lunar limb, and so is viewed from the side by an observer on the Earth. To the northwest is the crater Scott, a formation of similar...
and Scott
Scott (crater)
Scott is a lunar impact crater near the south pole of the Moon. Its location close to the lunar limb hinders observation, both from the foreshortening of the crater as seen from Earth and from the limited sunlight that enters the basin. In fact the northern end of this crater is in near perpetual...
, named after two other early explorers of the Antarctic
Antarctic
The Antarctic is the region around the Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica and the ice shelves, waters and island territories in the Southern Ocean situated south of the Antarctic Convergence...
continent.
Exploration
From the perspective of the EarthEarth
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...
, this crater lies along the southern limb of the Moon, making observation difficult. Detailed mapping of the polar regions and farside of the Moon did not occur until the advent of orbiting spacecraft. Shackleton lies entirely within the rim of the immense South Pole-Aitken basin
South Pole-Aitken basin
The South Pole-Aitken basin is an impact crater on Earth's Moon. Roughly in diameter and deep, it is one of the largest known impact craters in the Solar System. It is the largest, oldest and deepest basin recognized on the Moon. This moon basin was named for two features on opposing sides; the...
, which is one of the largest known impact formations in the Solar System
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...
. This basin is over 12 kilometers deep, and an exploration of its properties could provide useful information about the lunar interior.
A neutron
Neutron
The neutron is a subatomic hadron particle which has the symbol or , no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen, nuclei of atoms consist of protons and neutrons, which are therefore collectively referred to as nucleons. The number of...
spectrometer
Spectrometer
A spectrometer is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify materials. The variable measured is most often the light's intensity but could also, for instance, be the polarization...
on board the Lunar Prospector
Lunar Prospector
The Lunar Prospector mission was the third selected by NASA for full development and construction as part of the Discovery Program. At a cost of $62.8 million, the 19-month mission was designed for a low polar orbit investigation of the Moon, including mapping of surface composition and possible...
spacecraft detected enhanced concentrations of hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
close to the northern and southern lunar poles, including the crater Shackleton. At the end of this mission in July 1999, the spacecraft was crashed into the nearby crater Shoemaker
Shoemaker (lunar crater)
Shoemaker is a lunar crater that is 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...
in the hope of detecting from Earth-based telescopes an impact-generated plume containing water vapor. The impact event did not produce any detectable water vapor, and this may be an indication that the hydrogen is not in the form of hydrate
Hydrate
Hydrate is a term used in inorganic chemistry and organic chemistry to indicate that a substance contains water. The chemical state of the water varies widely between hydrates, some of which were so labeled before their chemical structure was understood....
d mineral
Mineral
A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
s, or that the impact site did not contain any ice. Alternatively, it is possible that the crash did not excavate deeply enough into the regolith
Regolith
Regolith is a layer of loose, heterogeneous material covering solid rock. It includes dust, soil, broken rock, and other related materials and is present on Earth, the Moon, some asteroids, and other terrestrial planets and moons.-Etymology:...
to liberate significant quantities of water vapor.
From images of the crater edge taken from orbit, Shackleton appears to be relatively intact; much like a young crater that has not been significantly eroded from subsequent impacts. This may mean that the inner sides are relatively steep, which may make traversing the sides relatively difficult for a robotic vehicle. In addition, it is possible that the interior floor might not have collected a significant quantity of volatiles since its formation. However other craters in the vicinity are considerably older, and may contain significant deposits of hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
, possibly in the form of water ice. (See Shoemaker (lunar crater)
Shoemaker (lunar crater)
Shoemaker is a lunar crater that is 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...
, for example.)
Radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
studies following the Lunar Prospector mission demonstrate that the inner walls of Shackleton are similar in reflective characteristics
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...
to those of some sunlit craters. In particular, the surroundings appear to contain a significant number of blocks in its ejecta blanket, suggesting that its radar properties are a result of surface roughness, and not ice deposits, as was previously suggested from a radar experiment involving the Clementine mission
Clementine mission
Clementine was a joint space project between the Ballistic Missile Defense Organization and NASA...
. This interpretation, however, is not universally agreed upon within the scientific community. Radar images of the crater at a wavelength of 13 cm show no evidence for water ice deposits.
Optical imaging inside the crater was done for the first time by the Japanese lunar orbiter spacecraft Kaguya
SELENE
SELENE , better known in Japan by its nickname after the legendary Japanese moon princess, was the second Japanese lunar orbiter spacecraft. Produced by the Institute of Space and Astronautical Science and the National Space Development Agency , both now part of the Japan Aerospace Exploration...
in 2007. It did not have any evidence of significant amount of water ice, down to the image resolution of 10 m per pixel.
On November 15, 2008, a 34-kg probe made a hard landing near the crater. The moon impact probe (MIP) was launched from the Indian Chandrayaan-I spacecraft and reached the surface 25 minutes later. The probe carried a radar altimeter, video imaging system, and a mass spectrometer, which will be used to search for water.
Potential uses
Some sites along Shackleton's rim receive almost constant illumination. At these locales sunlight is almost always available for conversion into electricityElectricity
Electricity is a general term encompassing a variety of phenomena resulting from the presence and flow of electric charge. These include many easily recognizable phenomena, such as lightning, static electricity, and the flow of electrical current in an electrical wire...
using solar panel
Photovoltaic module
A solar panel is a packaged, connected assembly of solar cells, also known as photovoltaic cells...
s, potentially making them good locations for future Moon landing
Moon landing
A moon landing is the arrival of a spacecraft on the surface of the Moon. This includes both manned and unmanned missions. The first human-made object to reach the surface of the Moon was the Soviet Union's Luna 2 mission on 13 September 1959. The United States's Apollo 11 was the first manned...
s. The temperature at this site is also more favorable than at more equatorial latitudes as it does not experience the daily temperature extremes of 100 °C when the Sun is overhead, to as low as −150 °C during the lunar night.
While scientific experiments performed by Clementine
Clementine mission
Clementine was a joint space project between the Ballistic Missile Defense Organization and NASA...
and Lunar Prospector
Lunar Prospector
The Lunar Prospector mission was the third selected by NASA for full development and construction as part of the Discovery Program. At a cost of $62.8 million, the 19-month mission was designed for a low polar orbit investigation of the Moon, including mapping of surface composition and possible...
could indicate the presence of water in the polar craters, the current evidence is far from definitive. There are doubts among scientists as to whether or not the hydrogen is in the form of ice, as well as to the concentration of this "ore" with depth below the surface. Resolution of this issue will require future missions to the Moon. The presence of water suggests that the crater floor could potentially be "mined" for deposits of hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
in water form, a commodity that is expensive to deliver directly from the Earth.
This crater has also been proposed as a future site for a large 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...
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...
. The low temperature of the crater floor makes it ideal for infrared observations, and solar cell
Solar cell
A solar cell is a solid state electrical device that converts the energy of light directly into electricity by the photovoltaic effect....
s placed along the rim could provide near-continuous power to the observatory. About 120 kilometers from the crater lies the 5-km tall Malapert Mountain, a peak that is perpetually visible 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...
, and which could serve as a radio
Radio
Radio is the transmission of signals through free space by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space...
relay station when suitably equipped.
NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
has named the rim of Shackleton as a potential candidate for its lunar outpost
Lunar outpost (NASA)
A lunar outpost was an element of the George W. Bush era Vision for Space Exploration, which has been replaced with President Barack Obama's space policy. The outpost would have been an inhabited facility on the surface of the Moon. At the time it was proposed, NASA was to construct the outpost...
, slated to be up and running by 2020 and continuously staffed by a crew by 2024. The location would promote self-sustainability for lunar residents, as perpetual sunlight on the south pole would provide energy for solar panels. Furthermore, the shadowed polar regions are believed to contain the frozen water necessary for human consumption and could also be harvested for fuel manufacture.
See also
- Colonization of the MoonColonization of the MoonThe colonization of the Moon is the proposed establishment of permanent human communities on the Moon. Advocates of space exploration have seen settlement of the Moon as a logical step in the expansion of humanity beyond the Earth. Recent indication that water might be present in noteworthy...
- Lunar ice
- Lunar south poleLunar south poleThe lunar south pole is of special interest to scientists because of the postulated occurrence of ice in permanently shadowed areas. Of the lunar poles, the south pole is of greater interest because the area that remains in shadow is much larger than that at the north pole. The lunar south pole...