jantonio09
Posted: Wed Jan 27, 2010 8:18 amWhat are the implications of the discovery of water on the Monn?
The discovery of large quantities of water on the moon will have very significant implications for human space exploration, according to space expert Chris Welch. The findings by NASA, which have been hitting the headlines recently, were reportedly made after researchers examined data from three separate missions to the moon. Welch, an astronautics and space systems expert at Kingston University London’s Faculty of Engineering, said the findings could transform work for astronauts.
“Scientists thought they knew fairly accurately what the surface of the moon was like, and these results show that they didn't — or at least not completely,” Welch said. “Finding so much more water could make living on the moon much easier in the future. Water is very heavy, and to have to launch it into space would be difficult and expensive. If there is water on the moon — in whatever form — then we have a potential reservoir that could be used for drinking or to make into hydrogen and oxygen, which could be used as rocket propellant. Also, of course, we could use the oxygen to breathe.”
Current thinking is that the water comes from particles in the solar wind, which is emitted by and streams away from the sun continuously, Welch, winner of the 2009 Sir Arthur Clarke Award for Achievement in Space Education, explained. The wind strikes the soil on the surface of the moon, which has no magnetic field or atmosphere to protect it, and stimulates chemical reactions in which oxygen atoms in the soil combine with hydrogen nuclei to form water (H2O) and hydroxyl (HO) molecules, he said.
“The water is thought to exist as a very fine film covering the particles of the lunar soil, or as groups of molecules, not as a liquid,” Welch explained. “You couldn’t drink it in its current form but, if extracted, then you certainly could. It has been suggested that one cubic meter of soil might provide one liter of water.”
Earlier estimates suggested that there could be more than 300 million tons of water ice on the moon, and these new results suggest that it could be even more, Welch said. The water is not in the form as we know it on Earth. “The water is on the main lunar surface which is slightly 'damp' soil and rocks,” Welch said. “These are still much dryer than any on Earth, though. At the poles of the moon, it is thought that water ice may exist in craters that have been in shadow for millions of years and which act as 'cold traps' for water vapor that might arrive either from comets impacts or, now, from the rest of the surface.”
While groundbreaking, Welch does not believe the new findings show there is or could once have been life on the moon. He believes further research is needed. “There need to be more detailed science missions, preferably with astronauts landing on the moon, to analyze the soil in space. On October 9, 2009, NASA LCROSS spacecraft is due to carry out two impacts on polar craters to see if it can throw up evidence of water ice.”
Many cultures have stories and myths about the Moon. Can you find one that like?
The story of the fateful night when Chang'e was lifted up to the moon, familiar to most Chinese citizens, is a favorite subject of poets. Unlike many lunar deities in other cultures who personify the moon, Chang'e simply lives on the moon but is not the moon per se. Tradition places Houyi and Chang'e around 2170 BC, in the reign of the legendary Emperor Yao, shortly after that of Huangdi.
There are so many variations and adaptations of the Chang'e legend that one can become overwhelmed and utterly confused. However, most legends about Chang'e in Chinese mythology involve some variation of the following elements: Houyi, the Archer, Chang'e, the mythical Moon Goddess of Immortality; an emperor, either benevolent or malevolent; an elixir of life; and the Moon:
Once upon a time, the earth had ten suns. They burned the crops and people suffered infertility. Houyi sympathized with humans, so he decided to shoot down nine suns and leave one for the benefit of the people. After he shot down the suns, he was treated as a hero. He had a beautiful wife named Chang'e, and they lived happily together. Houyi had a many apprentices; they followed him to learn hunting. One day, on Houyi’s way back home, the emperor of the immortals gave Houyi two potions, each of which granted eternal life as a reward for shooting down the suns, one was for Houyi, and the other for his wife. He warned Houyi, “Make no haste to swallow the potion.” Houyi was to wait until New Years Day, on which he and Chang'e were supposed to eat the potion together. Chang’e put the potion in her jewelry box for safekeeping. But Peng, one of Houyi’s apprentices, discovered their secret and decided to steal the potion. One day, when Houyi and other apprentices went to the mountain, Peng pretended to be sick so that he could stay home. After everyone had gone to the mountain, Peng sneaked into Chang’e’s room and forced her to give him the potion. Chang’e knew she couldn't fight Peng, so she ate the potion herself. However, after eating it alone, she began to float. Unable to come back to earth, she took flight and flew far, far away. She did not want to leave her husband, so she stopped at the moon, which is the body closest to Earth. After Houyi found out what happened, he was very angry and heartbroken. He looked up into the night and called Chang’e’s name. He discovered that inside the moon there was a lady’s shadow that look like Chang’e, so he ran and ran and tried to reach the moon. He failed due to the wind.
The Apollo 11 mission was the first to put people on the Moon. What can you find out about the other missions that sent people to the Moon?
Apollo 12 was the sixth manned flight in the Apollo program and the second to land on the Moon. The mission was commanded by Charles "Pete" Conrad. It was launched on November 14, 1969, four months after Apollo 11. The landing site for the mission was the Ocean of Storms. Key objectives were achievement of a more precise landing (which had not been achieved by Apollo 11), and to visit the Surveyor 3 probe to remove parts for analysis. The mission ended on November 24 with a successful splashdown having completed the main mission parameters successfully.
Apollo 13 was the third manned mission by NASA that was intended to land on the moon, but a mid-mission technical malfunction forced the lunar landing to be aborted. The mission launched on April 11, 1970 at 13:13 CST. Two days later, while the mission was en route to the moon, a fault in the electrical system of one of the Service Module's oxygen tanks produced an explosion which caused a loss of electrical power and failure of both oxygen tanks. The command module remained functional on its own batteries and oxygen tank, which were only designed to support the vehicle during the last hours of flight. The crew shut down the Command Module and used the Lunar Module as a "lifeboat" during the return trip to earth. Despite great hardship caused by limited power, loss of cabin heat, and a shortage of potable water, the crew returned safely to Earth, and the mission was termed a "successful failure." A misquotation of a radio transmission by Swigert has become widely quoted in popular culture: "Houston, we have a problem.
Apollo 14 was the eighth manned mission in the Apollo programm and the third mission to land on the Moon. The nine-day mission was launched on January 31, 1971, with lunar touch down on February 5. The Lunar Module landed in the Fra Mauro formation; this had originally been the target of the ill-fated Apollo 13 mission. During the two lunar EVA’s over 100 pounds of moon rocks were collected and several surface experiments, including seismic studies, were carried out. Commander Alan Shepard famously hit two golf balls on the lunar surface with a make-shift club he had brought from Earth. Command Module Pilot Stuart Roosa took several hundred seeds on the mission, many of which were germinated on return resulting in the so called Moon trees.
Apollo 15 was the ninth manned mission in the Apollo program, the fourth mission to land on the Moon and the eighth successful manned mission. It was the first of what were termed "J missions", long duration stays on the Moon with a greater focus on science than had been possible on previous missions. It was also the first mission where the Lunar rover was used.The mission began on July 26, 1971, and concluded on August 7. NASA called it the most successful manned flight ever achieved.
The mission was the first not to land in a Lunar mare, instead landing near Hadley rille in an area of the Mare Imbrium called Palus Putredinus (Marsh of Decay). The crew explored the area using the first Lunar Rover allowing them to travel much farther from the Lunar Module lander than had previously been possible. They collected a total of 77 kg (170 lbs) of lunar surface material.
Apollo 16 was the tenth manned mission in the Apollo program, the fifth mission to land on the Moon and the first to land in a highlands area. The mission was launched on April 16, 1972, and concluded on April 27. It was a J-class mission, featuring a Lunar Rover and it brought back 94.7 kg of lunar samples. It included three lunar EVA: 7.2 hours, 7.4 hours, 5.7 hours and one trans-earth EVA of 1.4.
The Apollo 16 subsatellite was launched from the CSM while it was in lunar orbit. The subsatellite carried out experiments on magnetic fields and solar particles. It was launched April 24, 1972 at 21:56:09 UTC and orbited the Moon for 34 days and 425 revolutions. It had a mass of 80 lb (36 kg) and consisted of a central cylinder and three 1.5 m booms.
En route to the moon, the Apollo 16 astronauts took several photos of Earth, one of which was with North America in the background, with much of the northern portion of the continent under extensive cloud cover.
Despite a malfunction in the Command Module which almost aborted the lunar landing, Apollo 16 landed successfully in the Descartes Highlands on April 21.
Apollo 17 was the eleventh manned space mission in the NASA Apollo program. It was the first night launch of a U.S. human spaceflight and the sixth and final lunar landing mission of the Apollo program. The mission was launched at 12:33 a.m. EST on December 7, 1972, and concluded on December 19. It remains the most recent manned moon landing and the most recent manned flight beyond low Earth orbit. It also broke several records set by previous flights, including longest manned lunar landing flight; longest total lunar surface extravehicular activities; largest lunar sample return, and longest time in lunar orbit.
Apollo 18, Apollo 19, Apollo 20, and Apollo 21 Several missions of the Apollo program were canceled during the 1970s, due to budget limitations or schedule constraints. The most notable of these were three Moon landing missions, Apollos 18, 19 and 20, which had received some level of planning, but there were a variety of later planned flights. Some of these were incorporated into the Apollo Applications Program, of which the only result was the Skylab space station.
How has information about the Moon been of use here on Earth?
All this information can be used on Earth
Internal structure
The Moon is a differentiated body, being composed of a geochemically distinct crust, mantle, and core. This structure is hypothesized to have resulted from the fractional crystallization of a magma ocean shortly after its formation, at about 4.4 billion years ago.The energy required to melt the outer portion of the Moon is commonly attributed to a giant impact event that is postulated to have formed the Earth-Moon system, and the subsequent reaccretion of material in Earth orbit. Crystallization of this magma ocean would have given rise to a mafic mantle and a plagioclase-rich crust (see Origin and geologic evolution below).
Geochemical mapping from orbit implies that the crust of the Moon is largely anorthositic in composition consistent with the magma ocean hypothesis. In terms of elements, the crust is composed primarily of oxygen (41% to 46% by mass), silicon (21%), magnesium (6%), iron (13%), calcium (8%), and aluminium (7%). Based on geophysical techniques, its thickness is estimated to be on average about 50 km.
Partial melting within the mantle of the Moon gave rise to the eruption of mare basalts on the lunar surface. Analyses of these basalts indicate that the mantle is composed predominantly of the minerals olivine, orthopyroxene and clinopyroxene, and that the lunar mantle is more iron rich than that of the Earth. Some lunar basalts contain high abundances of titanium (present in the mineral ilmenite), suggesting that the mantle is highly heterogeneous in composition. Moonquakes have been found to occur deep within the mantle of the Moon about a thousand kilometres below the surface. These occur with monthly periodicities and are related to tidal stresses caused by the eccentric orbit of the Moon about the Earth.]
The Moon has a mean density of 3 346.4 kg/m³, making it the second densest moon in the Solar System after Io. Nevertheless, several lines of evidence imply that the core of the Moon is small, with a radius of about 350 km or less. This corresponds to only about 20% the size of the Moon, in contrast to about 50% as is the case for most other terrestrial bodies. The composition of the lunar core is not well constrained, but most believe that it is composed of metallic iron alloyed with a small amount of sulfur and nickel. Analyses of the Moon's time-variable rotation indicate that the core is at least partly molten.
Topography
The topography of the Moon has been measured by the methods of laser altimetry and stereo image analysis, most recently from data obtained during the Clementine mission. The most visible topographic feature is the giant far side South Pole-Aitken basin, which possesses the lowest elevations of the Moon. The highest elevations are found just to the north-east of this basin, and it has been suggested that this area might represent thick eject deposits that were emplaced during an oblique South Pole-Aitken basin impact event. Other large impact basins, such as Imbrium, Serenitatis, Crisium, Smythii, and Orientale, also possess regionally low elevations and elevated rims. Another distinguishing feature of the Moon's shape is that the elevations are on average about 1.9 km higher on the far side than the near side.]
Gravity field
The gravitational field of the Moon has been determined through tracking of radio signals emitted by orbiting spacecraft. The principle used depends on the Doppler effect, whereby the spacecraft acceleration in the line-of-sight direction can be determined by means of small shifts in frequency of the radio signal, and the distance from the spacecraft to a station on Earth. However, because of the Moon's synchronous rotation it is not possible to track spacecraft much over the limbs of the Moon, and the farsid gravity field is thus only poorly characterise.
The major characteristic of the Moon's gravitational field is the presence of mascons, which are large positive gravitational anomalies associated with some of the giant impact basins. These anomalies greatly influence the orbit of spacecraft about the Moon, and an accurate gravitational model is necessary in the planning of both manned and unmanned missions. The mascons are in part due to the presence of dense mare basaltic lava flows that fill some of the impact basins. However, lava flows by themselves can not explain the entirety of the gravitational signature, and uplift of the crust-mantle interface is required as well. Based on Lunar Prospector gravitational models, it has been suggested that some mascons exist that do not show evidence for mare basaltic volcanism.The huge expanse of mare basaltic volcanism associated with Oceanus Procellarum does not possess a positive gravitational anomaly.
Magnetic field
The Moon has an external magnetic field of the order of one to a hundred nanoteslas—less than one hundredth that of the Earth, which is 30–60 microteslas. Other major differences are that the Moon does not currently have a dipolar magnetic field (as would be generated by a geodynamo in its core), and the magnetizations that are present are almost entirely crustal in origin. One hypothesis holds that the crustal magnetizations were acquired early in lunar history when a geodynamo was still operating. The small size of the lunar core, however, is a potential obstacle to this theory. Alternatively, it is possible that on an airless body such as the Moon, transient magnetic fields could be generated during large impact events. In support of this, it has been noted that the largest crustal magnetizations appear to be located near the antipodes of the giant impact basins. It has been proposed that such a phenomenon could result from the free expansion of an impact generated plasma cloud around the Moon in the presence of an ambient magnetic field.
Atmosphere
The Moon has an atmosphere so thin as to be almost negligible, with a total atmospheric mass of less than 104 kg. The effective surface pressure of this small mass is around 3 × 10-15 atm (0.3 nPa). This pressure varies, of course, with the diurnal moon cycle. One source of its atmosphere is outgassing—the release of gases such as radon that originate by radioactive decay processes within the crust and mantle. Another important source is generated through the process of sputtering, which involves the bombardment of micrometeorites, solar wind ions, electrons, and sunlight. Gases that are released by sputtering can either reimplant into the regolith as a result of the Moon's gravity, or can be lost to space either by solar radiation pressure or by being swept away by the solar wind magnetic field if they are ionised. The elements sodium (Na) and potassium (K) have been detected using earth-based spectroscopic methods, whereas the element radon-222 (Rn) and polonium-210 (210Po) have been inferred from data obtained from the Lunar Prospector alpha particle spectrometer.] Argon-40 (40Ar), helium-4 (4He), oxygen (O2) and/or methane (CH4), nitrogen (N2) and/or carbon monoxide (CO), and carbon dioxide (CO2) were detected by in-situ detectors placed by the Apollo astronauts.
Surface temperature
During the lunar day, the surface temperature averages 107 °C, and during the lunar night, it averages −153 °C.
The Moon has the coldest place in the Solar System measured by a spacecraft.
NASA's Lunar Reconnaissance Orbiter has used its Diviner instrument to probe the insides of permanently shadowed craters on Earth's satellite. It found mid-winter, night-time surface temperatures inside the coldest craters in the northern polar region can dip as low as minus 249 °C (26 kelvins). The Diviner instrument observed the lowest summer temperatures in the darkest craters at the southern pole to be about 35 K (−238 °C); but in the north, close to the winter solstice the instrument recorded a temperature of just 26 K on the south-western edge of the floor of Hermite Crater.
Calculations suggest one would have to travel to a distance beyond the Kuiper Belt—well beyond the orbit of Neptune—to find objects with surfaces this cold. The discovery adds further weight to the idea that some craters on the Moon could harbour water-ices for extended periods, and also more volatile substances that require even colder storage temperatures.
Lunar atmosphere
The Moon has almost no atmosphere, because of its weak gravity. All types of gas will escape from its surface.
Without an atmosphere, there is no wind or water erosion. The Moon's surface is about the same now as it was 3 billion years ago. The astronauts' footprints remain unchanged on the Moon's surface. The footprints should last at least 10 million years.
Temperatures on the moon
The surface temperature fluctuates from roughly +300° F during the 2-week daytime to -270 F during the 2-week night. This is because there is not enough atmosphere to keep the Moon warm at night, nor protect it from the Sun's rays in the daytime. If you are wondering what to wear, an astronaut's suit is the most appropriate answer.
Rotation of moon
The same side of the Moon always faces the Earth. The Moon's rotation period is synchronous with its revolution period around the Earth.
Change of distance
Because of a loss of orbital energy to gravity from the Earth, the Moon is very gradually moving away from the Earth. In the very early history of the Earth, the Moon looked about 3 times larger in apparent size in the sky, because it was closer to the Earth.
Size comparison
The volume of the Earth's moon is the same as the volume of the Pacific Ocean.
Lunar magnetic field
The Moon has no global magnetic field. You cannot use a compass to find your direction.
Strange Mathematics: 1/2 equals 1/4
A quarter moon and a half moon are the same thing. The quarter refers to the fraction of the lunar month which has passed, whilst the half describes the portion of the Moon's disc which is visible.
Calculation of the Easter date
Easter is the first Sunday after the first Saturday after the first full moon after the equinox. (The equinox is quite often March 21, but can also occur on the March 20 or 22.)
Tides and the moon
The moon causes many of the tides in the Earth's oceans. This is because of the gravity force between the Earth and Moon. At full Moon and new Moon, the Sun, Earth and Moon are lined up, producing the higher than normal tides (called spring tides, for the way they spring up). When the Moon is at first or last quarter, smaller neap tides form.
Sun and Moon Eclipses
An eclipse of the Sun can occur only at New Moon, while an eclipse of the Moon can occur only at Full Moon.
The discovery of large quantities of water on the moon will have very significant implications for human space exploration, according to space expert Chris Welch. The findings by NASA, which have been hitting the headlines recently, were reportedly made after researchers examined data from three separate missions to the moon. Welch, an astronautics and space systems expert at Kingston University London’s Faculty of Engineering, said the findings could transform work for astronauts.
“Scientists thought they knew fairly accurately what the surface of the moon was like, and these results show that they didn't — or at least not completely,” Welch said. “Finding so much more water could make living on the moon much easier in the future. Water is very heavy, and to have to launch it into space would be difficult and expensive. If there is water on the moon — in whatever form — then we have a potential reservoir that could be used for drinking or to make into hydrogen and oxygen, which could be used as rocket propellant. Also, of course, we could use the oxygen to breathe.”
Current thinking is that the water comes from particles in the solar wind, which is emitted by and streams away from the sun continuously, Welch, winner of the 2009 Sir Arthur Clarke Award for Achievement in Space Education, explained. The wind strikes the soil on the surface of the moon, which has no magnetic field or atmosphere to protect it, and stimulates chemical reactions in which oxygen atoms in the soil combine with hydrogen nuclei to form water (H2O) and hydroxyl (HO) molecules, he said.
“The water is thought to exist as a very fine film covering the particles of the lunar soil, or as groups of molecules, not as a liquid,” Welch explained. “You couldn’t drink it in its current form but, if extracted, then you certainly could. It has been suggested that one cubic meter of soil might provide one liter of water.”
Earlier estimates suggested that there could be more than 300 million tons of water ice on the moon, and these new results suggest that it could be even more, Welch said. The water is not in the form as we know it on Earth. “The water is on the main lunar surface which is slightly 'damp' soil and rocks,” Welch said. “These are still much dryer than any on Earth, though. At the poles of the moon, it is thought that water ice may exist in craters that have been in shadow for millions of years and which act as 'cold traps' for water vapor that might arrive either from comets impacts or, now, from the rest of the surface.”
While groundbreaking, Welch does not believe the new findings show there is or could once have been life on the moon. He believes further research is needed. “There need to be more detailed science missions, preferably with astronauts landing on the moon, to analyze the soil in space. On October 9, 2009, NASA LCROSS spacecraft is due to carry out two impacts on polar craters to see if it can throw up evidence of water ice.”
Many cultures have stories and myths about the Moon. Can you find one that like?
The story of the fateful night when Chang'e was lifted up to the moon, familiar to most Chinese citizens, is a favorite subject of poets. Unlike many lunar deities in other cultures who personify the moon, Chang'e simply lives on the moon but is not the moon per se. Tradition places Houyi and Chang'e around 2170 BC, in the reign of the legendary Emperor Yao, shortly after that of Huangdi.
There are so many variations and adaptations of the Chang'e legend that one can become overwhelmed and utterly confused. However, most legends about Chang'e in Chinese mythology involve some variation of the following elements: Houyi, the Archer, Chang'e, the mythical Moon Goddess of Immortality; an emperor, either benevolent or malevolent; an elixir of life; and the Moon:
Once upon a time, the earth had ten suns. They burned the crops and people suffered infertility. Houyi sympathized with humans, so he decided to shoot down nine suns and leave one for the benefit of the people. After he shot down the suns, he was treated as a hero. He had a beautiful wife named Chang'e, and they lived happily together. Houyi had a many apprentices; they followed him to learn hunting. One day, on Houyi’s way back home, the emperor of the immortals gave Houyi two potions, each of which granted eternal life as a reward for shooting down the suns, one was for Houyi, and the other for his wife. He warned Houyi, “Make no haste to swallow the potion.” Houyi was to wait until New Years Day, on which he and Chang'e were supposed to eat the potion together. Chang’e put the potion in her jewelry box for safekeeping. But Peng, one of Houyi’s apprentices, discovered their secret and decided to steal the potion. One day, when Houyi and other apprentices went to the mountain, Peng pretended to be sick so that he could stay home. After everyone had gone to the mountain, Peng sneaked into Chang’e’s room and forced her to give him the potion. Chang’e knew she couldn't fight Peng, so she ate the potion herself. However, after eating it alone, she began to float. Unable to come back to earth, she took flight and flew far, far away. She did not want to leave her husband, so she stopped at the moon, which is the body closest to Earth. After Houyi found out what happened, he was very angry and heartbroken. He looked up into the night and called Chang’e’s name. He discovered that inside the moon there was a lady’s shadow that look like Chang’e, so he ran and ran and tried to reach the moon. He failed due to the wind.
The Apollo 11 mission was the first to put people on the Moon. What can you find out about the other missions that sent people to the Moon?
Apollo 12 was the sixth manned flight in the Apollo program and the second to land on the Moon. The mission was commanded by Charles "Pete" Conrad. It was launched on November 14, 1969, four months after Apollo 11. The landing site for the mission was the Ocean of Storms. Key objectives were achievement of a more precise landing (which had not been achieved by Apollo 11), and to visit the Surveyor 3 probe to remove parts for analysis. The mission ended on November 24 with a successful splashdown having completed the main mission parameters successfully.
Apollo 13 was the third manned mission by NASA that was intended to land on the moon, but a mid-mission technical malfunction forced the lunar landing to be aborted. The mission launched on April 11, 1970 at 13:13 CST. Two days later, while the mission was en route to the moon, a fault in the electrical system of one of the Service Module's oxygen tanks produced an explosion which caused a loss of electrical power and failure of both oxygen tanks. The command module remained functional on its own batteries and oxygen tank, which were only designed to support the vehicle during the last hours of flight. The crew shut down the Command Module and used the Lunar Module as a "lifeboat" during the return trip to earth. Despite great hardship caused by limited power, loss of cabin heat, and a shortage of potable water, the crew returned safely to Earth, and the mission was termed a "successful failure." A misquotation of a radio transmission by Swigert has become widely quoted in popular culture: "Houston, we have a problem.
Apollo 14 was the eighth manned mission in the Apollo programm and the third mission to land on the Moon. The nine-day mission was launched on January 31, 1971, with lunar touch down on February 5. The Lunar Module landed in the Fra Mauro formation; this had originally been the target of the ill-fated Apollo 13 mission. During the two lunar EVA’s over 100 pounds of moon rocks were collected and several surface experiments, including seismic studies, were carried out. Commander Alan Shepard famously hit two golf balls on the lunar surface with a make-shift club he had brought from Earth. Command Module Pilot Stuart Roosa took several hundred seeds on the mission, many of which were germinated on return resulting in the so called Moon trees.
Apollo 15 was the ninth manned mission in the Apollo program, the fourth mission to land on the Moon and the eighth successful manned mission. It was the first of what were termed "J missions", long duration stays on the Moon with a greater focus on science than had been possible on previous missions. It was also the first mission where the Lunar rover was used.The mission began on July 26, 1971, and concluded on August 7. NASA called it the most successful manned flight ever achieved.
The mission was the first not to land in a Lunar mare, instead landing near Hadley rille in an area of the Mare Imbrium called Palus Putredinus (Marsh of Decay). The crew explored the area using the first Lunar Rover allowing them to travel much farther from the Lunar Module lander than had previously been possible. They collected a total of 77 kg (170 lbs) of lunar surface material.
Apollo 16 was the tenth manned mission in the Apollo program, the fifth mission to land on the Moon and the first to land in a highlands area. The mission was launched on April 16, 1972, and concluded on April 27. It was a J-class mission, featuring a Lunar Rover and it brought back 94.7 kg of lunar samples. It included three lunar EVA: 7.2 hours, 7.4 hours, 5.7 hours and one trans-earth EVA of 1.4.
The Apollo 16 subsatellite was launched from the CSM while it was in lunar orbit. The subsatellite carried out experiments on magnetic fields and solar particles. It was launched April 24, 1972 at 21:56:09 UTC and orbited the Moon for 34 days and 425 revolutions. It had a mass of 80 lb (36 kg) and consisted of a central cylinder and three 1.5 m booms.
En route to the moon, the Apollo 16 astronauts took several photos of Earth, one of which was with North America in the background, with much of the northern portion of the continent under extensive cloud cover.
Despite a malfunction in the Command Module which almost aborted the lunar landing, Apollo 16 landed successfully in the Descartes Highlands on April 21.
Apollo 17 was the eleventh manned space mission in the NASA Apollo program. It was the first night launch of a U.S. human spaceflight and the sixth and final lunar landing mission of the Apollo program. The mission was launched at 12:33 a.m. EST on December 7, 1972, and concluded on December 19. It remains the most recent manned moon landing and the most recent manned flight beyond low Earth orbit. It also broke several records set by previous flights, including longest manned lunar landing flight; longest total lunar surface extravehicular activities; largest lunar sample return, and longest time in lunar orbit.
Apollo 18, Apollo 19, Apollo 20, and Apollo 21 Several missions of the Apollo program were canceled during the 1970s, due to budget limitations or schedule constraints. The most notable of these were three Moon landing missions, Apollos 18, 19 and 20, which had received some level of planning, but there were a variety of later planned flights. Some of these were incorporated into the Apollo Applications Program, of which the only result was the Skylab space station.
How has information about the Moon been of use here on Earth?
All this information can be used on Earth
Internal structure
The Moon is a differentiated body, being composed of a geochemically distinct crust, mantle, and core. This structure is hypothesized to have resulted from the fractional crystallization of a magma ocean shortly after its formation, at about 4.4 billion years ago.The energy required to melt the outer portion of the Moon is commonly attributed to a giant impact event that is postulated to have formed the Earth-Moon system, and the subsequent reaccretion of material in Earth orbit. Crystallization of this magma ocean would have given rise to a mafic mantle and a plagioclase-rich crust (see Origin and geologic evolution below).
Geochemical mapping from orbit implies that the crust of the Moon is largely anorthositic in composition consistent with the magma ocean hypothesis. In terms of elements, the crust is composed primarily of oxygen (41% to 46% by mass), silicon (21%), magnesium (6%), iron (13%), calcium (8%), and aluminium (7%). Based on geophysical techniques, its thickness is estimated to be on average about 50 km.
Partial melting within the mantle of the Moon gave rise to the eruption of mare basalts on the lunar surface. Analyses of these basalts indicate that the mantle is composed predominantly of the minerals olivine, orthopyroxene and clinopyroxene, and that the lunar mantle is more iron rich than that of the Earth. Some lunar basalts contain high abundances of titanium (present in the mineral ilmenite), suggesting that the mantle is highly heterogeneous in composition. Moonquakes have been found to occur deep within the mantle of the Moon about a thousand kilometres below the surface. These occur with monthly periodicities and are related to tidal stresses caused by the eccentric orbit of the Moon about the Earth.]
The Moon has a mean density of 3 346.4 kg/m³, making it the second densest moon in the Solar System after Io. Nevertheless, several lines of evidence imply that the core of the Moon is small, with a radius of about 350 km or less. This corresponds to only about 20% the size of the Moon, in contrast to about 50% as is the case for most other terrestrial bodies. The composition of the lunar core is not well constrained, but most believe that it is composed of metallic iron alloyed with a small amount of sulfur and nickel. Analyses of the Moon's time-variable rotation indicate that the core is at least partly molten.
Topography
The topography of the Moon has been measured by the methods of laser altimetry and stereo image analysis, most recently from data obtained during the Clementine mission. The most visible topographic feature is the giant far side South Pole-Aitken basin, which possesses the lowest elevations of the Moon. The highest elevations are found just to the north-east of this basin, and it has been suggested that this area might represent thick eject deposits that were emplaced during an oblique South Pole-Aitken basin impact event. Other large impact basins, such as Imbrium, Serenitatis, Crisium, Smythii, and Orientale, also possess regionally low elevations and elevated rims. Another distinguishing feature of the Moon's shape is that the elevations are on average about 1.9 km higher on the far side than the near side.]
Gravity field
The gravitational field of the Moon has been determined through tracking of radio signals emitted by orbiting spacecraft. The principle used depends on the Doppler effect, whereby the spacecraft acceleration in the line-of-sight direction can be determined by means of small shifts in frequency of the radio signal, and the distance from the spacecraft to a station on Earth. However, because of the Moon's synchronous rotation it is not possible to track spacecraft much over the limbs of the Moon, and the farsid gravity field is thus only poorly characterise.
The major characteristic of the Moon's gravitational field is the presence of mascons, which are large positive gravitational anomalies associated with some of the giant impact basins. These anomalies greatly influence the orbit of spacecraft about the Moon, and an accurate gravitational model is necessary in the planning of both manned and unmanned missions. The mascons are in part due to the presence of dense mare basaltic lava flows that fill some of the impact basins. However, lava flows by themselves can not explain the entirety of the gravitational signature, and uplift of the crust-mantle interface is required as well. Based on Lunar Prospector gravitational models, it has been suggested that some mascons exist that do not show evidence for mare basaltic volcanism.The huge expanse of mare basaltic volcanism associated with Oceanus Procellarum does not possess a positive gravitational anomaly.
Magnetic field
The Moon has an external magnetic field of the order of one to a hundred nanoteslas—less than one hundredth that of the Earth, which is 30–60 microteslas. Other major differences are that the Moon does not currently have a dipolar magnetic field (as would be generated by a geodynamo in its core), and the magnetizations that are present are almost entirely crustal in origin. One hypothesis holds that the crustal magnetizations were acquired early in lunar history when a geodynamo was still operating. The small size of the lunar core, however, is a potential obstacle to this theory. Alternatively, it is possible that on an airless body such as the Moon, transient magnetic fields could be generated during large impact events. In support of this, it has been noted that the largest crustal magnetizations appear to be located near the antipodes of the giant impact basins. It has been proposed that such a phenomenon could result from the free expansion of an impact generated plasma cloud around the Moon in the presence of an ambient magnetic field.
Atmosphere
The Moon has an atmosphere so thin as to be almost negligible, with a total atmospheric mass of less than 104 kg. The effective surface pressure of this small mass is around 3 × 10-15 atm (0.3 nPa). This pressure varies, of course, with the diurnal moon cycle. One source of its atmosphere is outgassing—the release of gases such as radon that originate by radioactive decay processes within the crust and mantle. Another important source is generated through the process of sputtering, which involves the bombardment of micrometeorites, solar wind ions, electrons, and sunlight. Gases that are released by sputtering can either reimplant into the regolith as a result of the Moon's gravity, or can be lost to space either by solar radiation pressure or by being swept away by the solar wind magnetic field if they are ionised. The elements sodium (Na) and potassium (K) have been detected using earth-based spectroscopic methods, whereas the element radon-222 (Rn) and polonium-210 (210Po) have been inferred from data obtained from the Lunar Prospector alpha particle spectrometer.] Argon-40 (40Ar), helium-4 (4He), oxygen (O2) and/or methane (CH4), nitrogen (N2) and/or carbon monoxide (CO), and carbon dioxide (CO2) were detected by in-situ detectors placed by the Apollo astronauts.
Surface temperature
During the lunar day, the surface temperature averages 107 °C, and during the lunar night, it averages −153 °C.
The Moon has the coldest place in the Solar System measured by a spacecraft.
NASA's Lunar Reconnaissance Orbiter has used its Diviner instrument to probe the insides of permanently shadowed craters on Earth's satellite. It found mid-winter, night-time surface temperatures inside the coldest craters in the northern polar region can dip as low as minus 249 °C (26 kelvins). The Diviner instrument observed the lowest summer temperatures in the darkest craters at the southern pole to be about 35 K (−238 °C); but in the north, close to the winter solstice the instrument recorded a temperature of just 26 K on the south-western edge of the floor of Hermite Crater.
Calculations suggest one would have to travel to a distance beyond the Kuiper Belt—well beyond the orbit of Neptune—to find objects with surfaces this cold. The discovery adds further weight to the idea that some craters on the Moon could harbour water-ices for extended periods, and also more volatile substances that require even colder storage temperatures.
Lunar atmosphere
The Moon has almost no atmosphere, because of its weak gravity. All types of gas will escape from its surface.
Without an atmosphere, there is no wind or water erosion. The Moon's surface is about the same now as it was 3 billion years ago. The astronauts' footprints remain unchanged on the Moon's surface. The footprints should last at least 10 million years.
Temperatures on the moon
The surface temperature fluctuates from roughly +300° F during the 2-week daytime to -270 F during the 2-week night. This is because there is not enough atmosphere to keep the Moon warm at night, nor protect it from the Sun's rays in the daytime. If you are wondering what to wear, an astronaut's suit is the most appropriate answer.
Rotation of moon
The same side of the Moon always faces the Earth. The Moon's rotation period is synchronous with its revolution period around the Earth.
Change of distance
Because of a loss of orbital energy to gravity from the Earth, the Moon is very gradually moving away from the Earth. In the very early history of the Earth, the Moon looked about 3 times larger in apparent size in the sky, because it was closer to the Earth.
Size comparison
The volume of the Earth's moon is the same as the volume of the Pacific Ocean.
Lunar magnetic field
The Moon has no global magnetic field. You cannot use a compass to find your direction.
Strange Mathematics: 1/2 equals 1/4
A quarter moon and a half moon are the same thing. The quarter refers to the fraction of the lunar month which has passed, whilst the half describes the portion of the Moon's disc which is visible.
Calculation of the Easter date
Easter is the first Sunday after the first Saturday after the first full moon after the equinox. (The equinox is quite often March 21, but can also occur on the March 20 or 22.)
Tides and the moon
The moon causes many of the tides in the Earth's oceans. This is because of the gravity force between the Earth and Moon. At full Moon and new Moon, the Sun, Earth and Moon are lined up, producing the higher than normal tides (called spring tides, for the way they spring up). When the Moon is at first or last quarter, smaller neap tides form.
Sun and Moon Eclipses
An eclipse of the Sun can occur only at New Moon, while an eclipse of the Moon can occur only at Full Moon.