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Lunar Regolith
Lunar soil is the fine fraction of the regolith found on the surface of the Moon. Its properties can differ significantly from those of terrestrial soil. The physical properties of lunar soil are primarily the result of mechanical disintegration of basaltic and anorthositic rock, caused by continual meteoric impacts and bombardment by solar and interstellar charged atomic particles over billions of years. The process is largely one of mechanical weathering in which the particles are ground to progressively finer size over time. This situation contrasts fundamentally to terrestrial dirt formation, mediated by the presence of molecular oxygen (O2), humidity, atmospheric wind, and a robust array of contributing biological processes. ''Lunar soil'' typically refers to only the finer fraction of lunar regolith, which is composed of grains 1 cm in diameter or less, but is often used interchangeably. Lunar dust generally connotes even finer materials than ''lunar soil''. Ther ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apollo 11 Bootprint
Apollo, grc, Ἀπόλλωνος, Apóllōnos, label=genitive , ; , grc-dor, Ἀπέλλων, Apéllōn, ; grc, Ἀπείλων, Apeílōn, label=Arcadocypriot Greek, ; grc-aeo, Ἄπλουν, Áploun, la, Apollō, la, Apollinis, label=genitive, , ; , is one of the Olympian deities in classical Greek and Roman religion and Greek and Roman mythology. The national divinity of the Greeks, Apollo has been recognized as a god of archery, music and dance, truth and prophecy, healing and diseases, the Sun and light, poetry, and more. One of the most important and complex of the Greek gods, he is the son of Zeus and Leto, and the twin brother of Artemis, goddess of the hunt. Seen as the most beautiful god and the ideal of the '' kouros'' (ephebe, or a beardless, athletic youth), Apollo is considered to be the most Greek of all the gods. Apollo is known in Greek-influenced Etruscan mythology as ''Apulu''. As the patron deity of Delphi (''Apollo Pythios''), Apollo is an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comminution
Comminution is the reduction of solid materials from one average particle size to a smaller average particle size, by crushing, grinding, cutting, vibrating, or other processes. In geology, it occurs naturally during faulting in the upper part of the Earth's crust. In industry, it is an important unit operation in mineral processing, ceramics, electronics, and other fields, accomplished with many types of mill. In dentistry, it is the result of mastication of food. In general medicine, it is one of the most traumatic forms of bone fracture. Within industrial uses, the purpose of comminution is to reduce the size and to increase the surface area of solids. It is also used to free useful materials from matrix materials in which they are embedded, and to concentrate minerals. Energy requirements The comminution of solid materials consumes energy, which is being used to break up the solid into smaller pieces. The comminution energy can be estimated by: * Rittinger's law, w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clay
Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay particles, but become hard, brittle and non–plastic upon drying or firing. Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impurities, such as a reddish or brownish colour from small amounts of iron oxide. Clay is the oldest known ceramic material. Prehistoric humans discovered the useful properties of clay and used it for making pottery. Some of the earliest pottery shards have been dated to around 14,000 BC, and clay tablets were the first known writing medium. Clay is used in many modern industrial processes, such as paper making, cement production, and chemical filtering. Between one-half and two-thirds of the world's population live or work in buildings made with clay, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mineral Hydration
In chemistry, mineral hydration is an inorganic chemical reaction which adds water to the crystal structure of a mineral, usually creating a new mineral, usually called a '' hydrate''. In geological terms, the process of mineral hydration is known as ''retrograde alteration'' and is a process occurring in retrograde metamorphism. It commonly accompanies metasomatism and is often a feature of wall rock alteration around ore bodies. Hydration of minerals occurs generally in concert with hydrothermal circulation which may be driven by tectonic or igneous activity. Processes There are two main ways in which minerals hydrate. One is conversion of an oxide to a double hydroxide, as with the hydration of calcium oxide—CaO—to calcium hydroxide—Ca(OH)2, the other is with the incorporation of water molecules directly into the crystalline structure of a new mineral. The later process is exhibited in the hydration of feldspars to clay minerals, garnet to chlorite, or kyan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apollo 15
Apollo 15 (July 26August 7, 1971) was the ninth crewed mission in the United States' Apollo program and the fourth to land on the Moon. It was the first J mission, with a longer stay on the Moon and a greater focus on science than earlier landings. Apollo 15 saw the first use of the Lunar Roving Vehicle. The mission began on July 26 and ended on August 7, with the lunar surface exploration taking place between July 30 and August 2. Commander David Scott and Lunar Module Pilot James Irwin landed near Hadley Rille and explored the local area using the rover, allowing them to travel further from the lunar module than had been possible on previous missions. They spent 18 hours on the Moon's surface on four extravehicular activities (EVA), and collected of surface material. At the same time, Command Module Pilot Alfred Worden orbited the Moon, operating the sensors in the scientific instrument module (SIM) bay of the service module. This suite of instruments col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hadley–Apennine (Moon)
Hadley–Apennine is a region on the near side of Earth's Moon that served as the landing site for the American Apollo 15 mission, the fourth manned landing on the Moon and the first of the " J-missions", in July 1971. The site is located on the eastern edge of Mare Imbrium on a lava plain known as Palus Putredinis. Hadley–Apennine is bordered by the Montes Apenninus (often referred to as "Apennine Front"), a mountain range, and Hadley Rille, a meandering channel, on the east and west, respectively. Data obtained from the composition of soil samples collected on Apollo 15 show that most (about 90%) of the samples from the Apennine Front are brown-glass breccias, and approximately 60–70% obtained from the mare surface are basalt. Although the basalts seem to vary in their texture, their ages appear to be approximately the same. Most of the samples obtained on the Apennine Front are KREEP (potassium, rare-earth elements, phosphorus) materials, anorthosites, recrystallized norit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apollo 17
Apollo 17 (December 7–19, 1972) was the final mission of NASA's Apollo program, the most recent time humans have set foot on the Moon or traveled beyond low Earth orbit. Commander Gene Cernan and Lunar Module Pilot Harrison Schmitt walked on the Moon, while Command Module Pilot Ronald Evans orbited above. Schmitt was the only professional geologist to land on the Moon; he was selected in place of Joe Engle, as NASA had been under pressure to send a scientist to the Moon. The mission's heavy emphasis on science meant the inclusion of a number of new experiments, including a biological experiment containing five mice that was carried in the command module. Mission planners had two primary goals in deciding on the landing site: to sample lunar highland material older than that at Mare Imbrium and to investigate the possibility of relatively recent volcanic activity. They therefore selected Taurus–Littrow, where formations that had been viewed and pictured from orbit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shorty Crater
Shorty is a feature on Earth's Moon, an impact crater in the Taurus–Littrow valley. Astronauts Eugene Cernan and Harrison Schmitt visited it in 1972, on the Apollo 17 mission. It is the location of the famous "orange soil", which geologists believe to be small bits of rapidly-cooled molten rock ejected in a fire fountain. It is about in diameter and up to deep. To the east of Shorty are Victory, Camelot, and the Apollo 17 landing site. To the southeast is Brontë. To the southwest are Lara and Nansen. The crater was named after the character "Shorty" in Richard Brautigan's 1967 novel ''Trout Fishing in America'', as well as to honor the genre of the short story with particular reference to J. D. Salinger. Apollo 17 Lunar Surface Journal, Corrected Transcript and Commentary Copyright 1995 by Eric M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Weathering
Space weathering is the type of weathering that occurs to any object exposed to the harsh environment of outer space. Bodies without atmospheres (including the Moon, Mercury, the asteroids, comets, and most of the moons of other planets) take on many weathering processes: * collisions of galactic cosmic rays and solar cosmic rays, * irradiation, implantation, and sputtering from solar wind particles, and * bombardment by different sizes of meteorites and micrometeorites. Space weathering is important because these processes affect the physical and optical properties of the surface of many planetary bodies. Therefore, it is critical to understand the effects of space weathering in order to properly interpret remotely sensed data. History Much of our knowledge of the space weathering process comes from studies of the lunar samples returned by the Apollo program, particularly the lunar soils (or regolith). The constant flux of high energy particles and micrometeorites, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmic Ray Spallation
Cosmic ray spallation, also known as the x-process, is a set of naturally occurring nuclear reactions causing nucleosynthesis; it refers to the formation of chemical elements from the impact of cosmic rays on an object. Cosmic rays are highly energetic charged particles from beyond Earth, ranging from protons, alpha particles, and nuclei of many heavier elements. About 1% of cosmic rays also consist of free electrons. Cosmic rays cause spallation when a ray particle (e.g. a proton) impacts with matter, including other cosmic rays. The result of the collision is the expulsion of particles (protons, neutrons, and alpha particles) from the object hit. This process goes on not only in deep space, but in Earth's upper atmosphere and crustal surface (typically the upper ten meters) due to the ongoing impact of cosmic rays. The process Cosmic ray spallation is thought to be responsible for the abundance in the universe of some light elements—lithium, beryllium, and boron—as well a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sputtering
In physics, sputtering is a phenomenon in which microscopic particles of a solid material are ejected from its surface, after the material is itself bombarded by energetic particles of a plasma or gas. It occurs naturally in outer space, and can be an unwelcome source of wear in precision components. However, the fact that it can be made to act on extremely fine layers of material is utilised in science and industry—there, it is used to perform precise etching, carry out analytical techniques, and deposit thin film layers in the manufacture of optical coatings, semiconductor devices and nanotechnology products. It is a physical vapor deposition technique. Physics When energetic ions collide with atoms of a target material, an exchange of momentum takes place between them. These ions, known as "incident ions", set off collision cascades in the target. Such cascades can take many paths; some recoil back toward the surface of the target. If a collision cascade reaches the surf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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