Lunar south pole
The lunar south pole is of special interest to scientists because of the occurrence of water ice in permanently shadowed areas around it. 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 craters are unique in that sunlight does not reach the bottom. Such craters are cold traps that contain a fossil record of the early solar system.
The lunar south pole is located on the center base of the far side of the Moon (80°S to 90°S) and covers a distance of about 1250 km. The lunar south pole has shifted 5 degrees from its original position billions of years ago. This shift has changed the rotational axis of the Moon, allowing sunlight to reach previously shadowed areas, but the south pole still contains some completely shadowed areas. The axis spin is 88.5 degrees from the plane of the elliptic. On the contrary, the pole also contains areas with permanent exposure to sunlight. The south pole contains many craters and basins such as the South Pole-Aitken basin, which appears to be one of the most fundamental features of the Moon, and mountains such as Epsilon Peak, which is taller than any mountain found on earth. The south pole is thermally benign, ranging at an average of 250–270 kelvins.
Spacecraft from several countries have explored the region around the lunar south pole. Extensive studies were conducted by the Lunar Orbiter, Clementine, Lunar Prospector, Lunar Reconnaissance Orbiter, Kaguya, and Chandrayaan. NASA's LCROSS mission found a significant amount of water in Cabeus. NASA’s LCROSS mission deliberately crashed into the floor of Cabeus and from samples found that it contained nearly 5% water.
The Lunar Reconnaissance Orbiter, or LRO, is a mission that has already begun and is currently mapping the lunar south pole. This mission will help scientists see if the Lunar south pole has enough sustainable resources to have a permanent station.The LRO had a Diviner Lunar Radiometer Experiment, commonly known as Diviner, on board which investigated the radiation and thermophysical properties of the south pole surface. The Diviner is designed to watch the thermal environment of the south pole. It can detect reflected solar radiation and internal infrared emissions. The LRO Diviner was able to detect where water and ice could be trapped on the surface.
The lunar south pole is deemed as an ideal spot for future landing missions and suitable for a lunar outpost. The permanently shadowed places on the Moon could contain ice and other minerals, which would be vital resources for future explorers. The mountain peaks near the pole are illuminated for large periods of time and could be used to provide solar energy to an outpost. With an outpost on the Moon scientists will be able to analyze fossil and water samples dating back to the beginning of the Solar System.
Connecting Ridge is the ridge that connects Shackleton Crater to the de Gerlache crater. Scientists used LOLA (Lunar Orbiter Laser Altimeter) which was a device used by NASA to provide an accurate topographic model of the Moon. With this data locations on the south pole were found that yielded sunlight for 92.27% – 95.65% of the time based on altitude ranging from 2m above ground to 10m above ground. At the same spots it was discovered that the longest continuous periods of darkness were only 3 to 5 days.
The Lunar South pole is a place where scientists may be able to use radio waves under 30 Hz. No place in space has been able to use radio waves of this frequency because the waves would interfere with Earth’s radio signals. The lunar south pole has mountains and basins that are not facing earth and would be an ideal place to project radio signals.
Lunar Mission One is a British-led, unmanned Moon mission announced in November 2014 and planned for 2024. It will attempt to land on the lunar south pole, then drill down at least 20m and possibly as deep as 100m. This could dramatically improve the understanding of the Moon's composition, its geologic history and formation, revealing new clues about the early Solar System. The mission is attempting to gain crowdfunding on Kickstarter.
Blue Origin is planning a mission to the south polar region in about 2020. This would lead to a series of missions landing equipment for a colony in a south polar region crater, using their Blue Moon lander.
The lunar south pole is one of the only spots in space that Illumination Conditions from the sun exist. These conditions at the Lunar South Pole have been observed using High Resolution Digital Terrain Models from LOLA. In addition to its illumination conditions, its surface can also reflect solar wind as energetic neutral atoms. On average, 16% of these atoms have been protons that varies based on location. These atoms have created an integral flux of backscattered hydrogen atoms due to the reflected amount of plasma that exists on the surface of the Moon. They also reveal the line boundary and the magnetic dynamics within the regions of these neutral atoms on the Moon' surface.
Cold traps are some of the important places on the lunar south pole in terms of possible water and iced deposits. Cold traps can contain water and ice that were originally from comets, meteorites and solar wind induced iron reduction. From experiments and sample readings scientists were able to confirm that cold traps do contain ice. Hydroxyl has also been found in these cold traps. The discovery of these two compounds has led to the founding of missions focusing primarily on the lunar poles using global scale infrared detection. The ice stays in these traps only because of the thermal behavior of the Moon. These thermal behaviors are controlled by thermophysical properties, scattered sunlight, thermal re-radiation, internal heat and light given off by the earth. With the cold temperatures in the cold traps delivering ice could be a possibility in the near future, since it would not melt.
In addition to the amount of cold traps discovered, there also exists areas of the Moon where the crust is magnetized. This is what is known as the magnetic anomaly that exists on the surface of the Moon due to the remnants of metal iron that was emplaced by the SPA basin-forming impactor. The observations of the Moon's surface were conducted using iron perspected maps to locate the concentration of iron that is embedded in the Moon's surface. However, the concentration of iron that was theorized to be in the basin was not present in the mappings, but other plausible ideas were still possible to detect this amount of iron. With regards to the SPA Impactor,the iron causing the magnetic fluctuations could still be present, but were not detected as they could be too deep in the Moon's crust for the mappings to detect or caused by another anomaly that did not involve metallic properties. In addition, the findings were proven inadequate due to the inconsistencies between the maps that were used and they were not able to detect the magnitude of the magnetic fluctuations that occurred from the Moon's surface.
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