1.
Mohs scale of mineral hardness
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The Mohs scale of mineral hardness is a qualitative ordinal scale characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. Created in 1812 by German geologist and mineralogist Friedrich Mohs, it is one of several definitions of hardness in materials science, while greatly facilitating the identification of minerals in the field, the Mohs scale does not show how well hard materials perform in an industrial setting. Despite its lack of precision, the Mohs scale is highly relevant for field geologists, the Mohs scale hardness of minerals can be commonly found in reference sheets. Reference materials may be expected to have a uniform Mohs hardness, the Mohs scale of mineral hardness is based on the ability of one natural sample of mineral to scratch another mineral visibly. The samples of matter used by Mohs are all different minerals, Minerals are pure substances found in nature. Rocks are made up of one or more minerals, as the hardest known naturally occurring substance when the scale was designed, diamonds are at the top of the scale. The hardness of a material is measured against the scale by finding the hardest material that the material can scratch. For example, if material is scratched by apatite but not by fluorite. Scratching a material for the purposes of the Mohs scale means creating non-elastic dislocations visible to the naked eye, frequently, materials that are lower on the Mohs scale can create microscopic, non-elastic dislocations on materials that have a higher Mohs number. The Mohs scale is an ordinal scale. For example, corundum is twice as hard as topaz, the table below shows the comparison with the absolute hardness measured by a sclerometer, with pictorial examples. On the Mohs scale, a streak plate has a hardness of 7.0, using these ordinary materials of known hardness can be a simple way to approximate the position of a mineral on the scale. The table below incorporates additional substances that may fall between levels, Comparison between Hardness and Hardness, Mohs hardness of elements is taken from G. V, samsonov in Handbook of the physicochemical properties of the elements, IFI-Plenum, New York, USA,1968. The Hardness of Minerals and Rocks
2.
Lustre (mineralogy)
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Lustre or luster is the way light interacts with the surface of a crystal, rock, or mineral. The word traces its origins back to the latin lux, meaning light, a range of terms are used to describe lustre, such as earthy, metallic, greasy, and silky. Similarly, the term refers to a glassy lustre. A list of terms is given below. Lustre varies over a continuum, and so there are no rigid boundaries between the different types of lustre. The terms are frequently combined to describe types of lustre. Some minerals exhibit unusual optical phenomena, such as asterism or chatoyancy, a list of such phenomena is given below. Adamantine minerals possess a superlative lustre, which is most notably seen in diamond, such minerals are transparent or translucent, and have a high refractive index. Minerals with an adamantine lustre are uncommon, with examples being cerussite. Minerals with a degree of lustre are referred to as subadamantine, with some examples being garnet. Dull minerals exhibit little to no lustre, due to coarse granulations which scatter light in all directions, a distinction is sometimes drawn between dull minerals and earthy minerals, with the latter being coarser, and having even less lustre. Greasy minerals resemble fat or grease, a greasy lustre often occurs in minerals containing a great abundance of microscopic inclusions, with examples including opal and cordierite. Many minerals with a greasy lustre also feel greasy to the touch, metallic minerals have the lustre of polished metal, and with ideal surfaces will work as a reflective surface. Examples include galena, pyrite and magnetite, pearly minerals consist of thin transparent co-planar sheets. Light reflecting from these layers give them a lustre reminiscent of pearls, such minerals possess perfect cleavage, with examples including muscovite and stilbite. Resinous minerals have the appearance of resin, chewing gum or plastic, a principal example is amber, which is a form of fossilized resin. Silky minerals have an arrangement of extremely fine fibres, giving them a lustre reminiscent of silk. Examples include asbestos, ulexite and the satin spar variety of gypsum, a fibrous lustre is similar, but has a coarser texture
3.
Mineral
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A mineral is a naturally occurring chemical compound, usually of crystalline form and abiogenic in origin. A mineral has one specific chemical composition, whereas a rock can be an aggregate of different minerals or mineraloids, the study of minerals is called mineralogy. There are over 5,300 known mineral species, over 5,070 of these have been approved by the International Mineralogical Association, the silicate minerals compose over 90% of the Earths crust. The diversity and abundance of species is controlled by the Earths chemistry. Silicon and oxygen constitute approximately 75% of the Earths crust, which translates directly into the predominance of silicate minerals, minerals are distinguished by various chemical and physical properties. Differences in chemical composition and crystal structure distinguish the various species, changes in the temperature, pressure, or bulk composition of a rock mass cause changes in its minerals. Minerals can be described by their various properties, which are related to their chemical structure. Common distinguishing characteristics include crystal structure and habit, hardness, lustre, diaphaneity, colour, streak, tenacity, cleavage, fracture, parting, more specific tests for describing minerals include magnetism, taste or smell, radioactivity and reaction to acid. Minerals are classified by key chemical constituents, the two dominant systems are the Dana classification and the Strunz classification, the silicate class of minerals is subdivided into six subclasses by the degree of polymerization in the chemical structure. All silicate minerals have a unit of a 4− silica tetrahedron—that is, a silicon cation coordinated by four oxygen anions. These tetrahedra can be polymerized to give the subclasses, orthosilicates, disilicates, cyclosilicates, inosilicates, phyllosilicates, other important mineral groups include the native elements, sulfides, oxides, halides, carbonates, sulfates, and phosphates. The first criterion means that a mineral has to form by a natural process, stability at room temperature, in the simplest sense, is synonymous to the mineral being solid. More specifically, a compound has to be stable or metastable at 25 °C, modern advances have included extensive study of liquid crystals, which also extensively involve mineralogy. Minerals are chemical compounds, and as such they can be described by fixed or a variable formula, many mineral groups and species are composed of a solid solution, pure substances are not usually found because of contamination or chemical substitution. Finally, the requirement of an ordered atomic arrangement is usually synonymous with crystallinity, however, crystals are also periodic, an ordered atomic arrangement gives rise to a variety of macroscopic physical properties, such as crystal form, hardness, and cleavage. There have been recent proposals to amend the definition to consider biogenic or amorphous substances as minerals. The formal definition of an approved by the IMA in 1995, A mineral is an element or chemical compound that is normally crystalline. However, if geological processes were involved in the genesis of the compound, Mineral classification schemes and their definitions are evolving to match recent advances in mineral science
4.
Tranquility Base
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Tranquility Base is the site on the Moon where, in 1969, humans landed and walked on another celestial body for the first time. On July 20,1969, Apollo 11 crewmembers Neil Armstrong and Buzz Aldrin landed their Apollo Lunar Module Eagle at approximately 20,17,40 UTC.5 pounds of dirt and they lifted off the surface on July 21 at 17,54 UTC. Tranquility Base has remained unvisited since then. S, for more than two years, NASA planners considered a collection of 30 potential sites for the first manned landing. Site number 2, centered at 0°42′50″N 23°42′28″E, was the Sea of Tranquility site ultimately chosen, since a precision landing was not expected on the first mission, the target area was an ellipse measuring 11.5 miles east-west by 3.0 miles north-south. Thus the landing was still within the target ellipse, Armstrong named the site at 20,17,58 UTC, approximately 18 seconds after his and Aldrins successful landing, as he announced, Houston, Tranquility Base here. During training, Armstrong and Aldrin had exclusively used the callsign Eagle in simulated ground conversations, Armstrong and Aldrin decided on using Tranquility Base just before the flight, telling only Capsule Communicator Charles Duke before the mission, so Duke would not be taken by surprise. The name has become a permanent designation for the site, unlike most names given to lunar landmarks by Apollo astronauts, the International Astronomical Union officially recognizes the designation Tranquility Base. It is listed on maps as Statio Tranquillitatis, conforming to the standard use of Latin names for lunar place names. About 100 man-made objects and footprints left by Armstrong and Aldrin remain at Tranquility Base, the descent stage of the Lunar Module remains at the original point of landing. According to Aldrin, the US flag planted at the site during their moonwalk was blown over by the ascent rocket exhaust, a laser reflector was placed at the site to allow precise ongoing measurements of the distance to the Moon from Earth. A solar-powered seismometer was also left to measure moonquakes, but this stopped functioning after 21 days, various gear that was no longer needed for the return phase of the mission – including Aldrins boots – was left behind to lighten the craft for return to lunar orbit. As the site of the first human landing on a body, Tranquility Base has cultural. The U. S. states of California and New Mexico have listed it on their heritage registers, since their laws require only that listed sites have some association with the state. Despite the location of Mission Control in Houston, Texas has not granted similar status to the site, one team, led by Astrobotic Technology, announced it would attempt to land a craft at Tranquility Base
5.
Moon
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The Moon is an astronomical body that orbits planet Earth, being Earths only permanent natural satellite. It is the fifth-largest natural satellite in the Solar System, following Jupiters satellite Io, the Moon is second-densest satellite among those whose densities are known. The average distance of the Moon from the Earth is 384,400 km, the Moon is thought to have formed about 4.51 billion years ago, not long after Earth. It is the second-brightest regularly visible celestial object in Earths sky, after the Sun and its surface is actually dark, although compared to the night sky it appears very bright, with a reflectance just slightly higher than that of worn asphalt. Its prominence in the sky and its cycle of phases have made the Moon an important cultural influence since ancient times on language, calendars, art. The Moons gravitational influence produces the ocean tides, body tides, and this matching of apparent visual size will not continue in the far future. The Moons linear distance from Earth is currently increasing at a rate of 3.82 ±0.07 centimetres per year, since the Apollo 17 mission in 1972, the Moon has been visited only by uncrewed spacecraft. The usual English proper name for Earths natural satellite is the Moon, the noun moon is derived from moone, which developed from mone, which is derived from Old English mōna, which ultimately stems from Proto-Germanic *mǣnōn, like all Germanic language cognates. Occasionally, the name Luna is used, in literature, especially science fiction, Luna is used to distinguish it from other moons, while in poetry, the name has been used to denote personification of our moon. The principal modern English adjective pertaining to the Moon is lunar, a less common adjective is selenic, derived from the Ancient Greek Selene, from which is derived the prefix seleno-. Both the Greek Selene and the Roman goddess Diana were alternatively called Cynthia, the names Luna, Cynthia, and Selene are reflected in terminology for lunar orbits in words such as apolune, pericynthion, and selenocentric. The name Diana is connected to dies meaning day, several mechanisms have been proposed for the Moons formation 4.51 billion years ago, and some 60 million years after the origin of the Solar System. These hypotheses also cannot account for the angular momentum of the Earth–Moon system. This hypothesis, although not perfect, perhaps best explains the evidence, eighteen months prior to an October 1984 conference on lunar origins, Bill Hartmann, Roger Phillips, and Jeff Taylor challenged fellow lunar scientists, You have eighteen months. Go back to your Apollo data, go back to computer, do whatever you have to. Dont come to our conference unless you have something to say about the Moons birth, at the 1984 conference at Kona, Hawaii, the giant impact hypothesis emerged as the most popular. Afterward there were only two groups, the giant impact camp and the agnostics. Giant impacts are thought to have been common in the early Solar System, computer simulations of a giant impact have produced results that are consistent with the mass of the lunar core and the present angular momentum of the Earth–Moon system
6.
Neil Armstrong
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Neil Alden Armstrong was an American astronaut and the first person to walk on the Moon. He was also an engineer, naval aviator, test pilot. Before becoming an astronaut, Armstrong was an officer in the U. S. Navy and he later completed graduate studies at the University of Southern California. A participant in the U. S. Air Forces Man in Space Soonest and X-20 Dyna-Soar human spaceflight programs and he made his first space flight as command pilot of Gemini 8 in March 1966, becoming NASAs first civilian astronaut to fly in space. He performed the first docking of two spacecraft, with pilot David Scott and this mission was aborted after Armstrong used some of his reentry control fuel to prevent a dangerous spin caused by a stuck thruster, in the first in-flight space emergency. Armstrongs second and last spaceflight was as commander of Apollo 11, along with Collins and Aldrin, Armstrong was awarded the Presidential Medal of Freedom by President Richard Nixon. President Jimmy Carter presented Armstrong the Congressional Space Medal of Honor in 1978, Armstrong and his former crewmates received the Congressional Gold Medal in 2009. Armstrong died in Cincinnati, Ohio on August 25,2012, at the age of 82, Armstrong was born on August 5,1930 near Wapakoneta, Ohio, the son of Stephen Koenig Armstrong and Viola Louise Engel. He was of German, Irish, and Scottish ancestry, and had a sister, June. His father worked as an auditor for the Ohio state government, Armstrongs love for flying grew during this time, having gotten off to an early start when his father took his two-year-old son to the Cleveland Air Races. When he was five, he experienced his first airplane flight in Warren, Ohio on July 20,1936 when he and his father took a ride in a Ford Trimotor and his fathers last move was in 1944, back to Wapakoneta. Armstrong attended Blume High School and took flying lessons at the grassy Wapakoneta airfield and he earned a student flight certificate on his 16th birthday, then soloed later in August, all before he had a drivers license. Armstrong was active in the Boy Scouts and earned the rank of Eagle Scout, as an adult, he was recognized by the Boy Scouts of America with its Distinguished Eagle Scout Award and Silver Buffalo Award. Houston replied, Thank you, Apollo 11, Im sure that, if they didnt hear that, theyll get the word through the news. Among the very few items that Neil Armstrong carried with him to the Moon. In 1947, at age 17, Armstrong began studying engineering at Purdue University. He was the person in his family to attend college. He was also accepted to the Massachusetts Institute of Technology, the only engineer he knew dissuaded him from attending, telling Armstrong that it was not necessary to go all the way to Cambridge, Massachusetts, for a good education
7.
Buzz Aldrin
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Buzz Aldrin is an American engineer and former astronaut. As the Lunar Module Pilot on Apollo 11, he was one of the first two humans to land on the Moon, and the person to walk on it. He set foot on the Moon at 03,15,16 on July 21,1969 and he is a former U. S. Air Force officer with the Command Pilot rating. Aldrin was born January 20,1930, in Mountainside Hospital, in Glen Ridge and his parents were Edwin Eugene Aldrin Sr. a career military man, and Marion Aldrin, who lived in neighboring Montclair. He is of Scottish, Swedish, and German ancestry, Aldrin was a Boy Scout and earned the rank of Tenderfoot Scout. The nickname Buzz originated in childhood, the younger of his two elder sisters mispronounced brother as buzzer, and this was shortened to Buzz, Aldrin made it his legal first name in 1988. Aldrin graduated third in his class at West Point in 1951 with a Bachelor of Science degree in mechanical engineering and he was commissioned as a Second Lieutenant in the United States Air Force and served as a jet fighter pilot during the Korean War. He flew 66 combat missions in F-86 Sabres and shot down two Mikoyan-Gurevich MiG-15 aircraft, the June 8,1953, issue of Life magazine featured gun camera photos taken by Aldrin of one of the Soviet pilots ejecting from his damaged aircraft. That same year, he graduated from the Squadron Officer School at Maxwell Air Force Base in Alabama and he flew F-100 Super Sabres as a flight commander at Bitburg Air Base, West Germany, in the 22d Fighter Squadron. In January 1963, Aldrin earned a Sc. D. degree in astronautics from the Massachusetts Institute of Technology, if only I could join them in their exciting endeavors. On completion of his doctorate, he was assigned to the Gemini Target Office of the Air Force Space Systems Division in Los Angeles before his selection as an astronaut, Aldrin was selected as a member of the third group of NASA astronauts in October 1963. Because test pilot experience was no longer a requirement, this was the first selection for which he was eligible, after the deaths of the original Gemini 9 prime crew, Elliot See and Charles Bassett, Aldrin and Jim Lovell were promoted to backup crew for the mission. He was confirmed as pilot on Gemini 12, the last Gemini mission and he set a record for EVA, demonstrating that astronauts could work outside spacecraft. Aldrin was chosen for the crew of Apollo 11 and made the first lunar landing with commander Neil Armstrong on July 20,1969. The next day, Aldrin became the person to walk on the Moon. Aldrins first words on the Moon were Beautiful view, then, in response to Armstrong asking, Isnt it magnificent. He was also the first person to urinate while on the Moon, there has been speculation about the extent of Aldrins desire at the time to be the first astronaut to walk on the Moon and its impact on his pre-flight, in-mission and post-flight actions. Also, Armstrong was the Mission Commander, and other astronauts who would command later Apollo missions were not sympathetic to Aldrins views
8.
Michael Collins (astronaut)
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Michael Collins, is an American former astronaut and test pilot. Selected as part of the group of fourteen astronauts in 1963. His first spaceflight was on Gemini 10, in which he and his second spaceflight was as the Command Module Pilot for Apollo 11. While he stayed in orbit around the Moon, Neil Armstrong and he is one of 24 people to have flown to the Moon. Collins was the person, and third American, to perform an EVA. Prior to becoming an astronaut, he attended the United States Military Academy and he was accepted to the U. S. Air Force Experimental Flight Test Pilot School at Edwards Air Force Base in 1960. He unsuccessfully applied for the astronaut group, but was accepted for the third group. After retiring from NASA in 1970 he took a job in the Department of State as Assistant Secretary of State for Public Affairs, a year later he became the director of the National Air and Space Museum. He held this position until 1978 when he stepped down to become undersecretary of the Smithsonian Institution, in 1980 he took the job as Vice President of LTV Aerospace. He resigned in 1985 to start his own business and he was married to Patricia Collins until her death in April 2014. They had three children, Kate, Ann, and Michael, Collins was born in Rome, Italy, on October 31,1930, to U. S. Army Major General James Lawton Collins, who served in the army for 38 years. For the first 17 years of his life, Collins called Rome, Oklahoma, Governors Island, New York, Puerto Rico, San Antonio, Texas and he took his first ride in a plane in Puerto Rico aboard a Grumman Widgeon. His father often told of how his own first plane ride had been in 1911 with Frank Lahm in the Philippines and he studied for two years in the Academia del Perpetuo Socorro in San Juan, Puerto Rico. After the United States entered World War II, the moved to Washington, D. C. where Collins attended St. Albans School. He graduated with a Bachelor of Science degree, finishing 185th out of 527 cadets in 1952, Lawton Collins, was the Chief of Staff of the United States Army. The Air Force Academy was in its construction phase. In the interim, graduates of the Military Academy, Naval Academy and he was chosen for advanced day fighter training at Nellis Air Force Base, Nevada, flying F-86 Sabres. This was followed by an assignment to the 21st Fighter-Bomber Wing at George Air Force Base, California and he transferred with the 21st when it was relocated to Chaumont-Semoutiers Air Base, France, in June 1954
9.
Apollo 11
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Apollo 11 was the spaceflight that landed the first two humans on the Moon. Mission commander Neil Armstrong and pilot Buzz Aldrin, both American, landed the lunar module Eagle on July 20,1969, at 20,18 UTC. Armstrong became the first to step onto the lunar surface six hours later on July 21 at 02,56,15 UTC and they spent about two and a quarter hours together outside the spacecraft, and collected 47.5 pounds of lunar material to bring back to Earth. Michael Collins piloted the command module Columbia alone in lunar orbit while they were on the Moons surface, Armstrong and Aldrin spent just under a day on the lunar surface before rendezvousing with Columbia in lunar orbit. Apollo 11 was launched by a Saturn V rocket from Kennedy Space Center in Merritt Island, Florida, on July 16, and was the fifth manned mission of NASAs Apollo program. After being sent toward the Moon by the Saturn Vs upper stage, Armstrong and Aldrin then moved into the lunar module Eagle and landed in the Sea of Tranquility. They stayed a total of about 21.5 hours on the lunar surface, the astronauts used Eagles upper stage to lift off from the lunar surface and rejoin Collins in the command module. They jettisoned Eagle before they performed the maneuvers that blasted them out of orbit on a trajectory back to Earth. They returned to Earth and landed in the Pacific Ocean on July 24, broadcast on live TV to a worldwide audience, Armstrong stepped onto the lunar surface and described the event as one small step for man, one giant leap for mankind. Apollo 11 was the second all-veteran multi-person crew in human spaceflight history, a previous solo veteran flight had been made on Soyuz 1 in 1967 by Soviet cosmonaut Vladimir Komarov. Collins was originally slated to be the Command Module Pilot on Apollo 8 but was removed when he required surgery on his back and was replaced by Jim Lovell, his backup for that flight. In early 1969, Anders accepted a job with the National Space Council effective August 1969, charlie Duke, Capsule Communicator Ronald Evans Owen K. Garriott Don L. Low to suggest the Apollo 11 crew be less flippant in naming their craft. During early mission planning, the names Snowcone and Haystack were used and put in the news release, the Command Module was named Columbia after the Columbiad, the giant cannon shell spacecraft fired by a giant cannon in Jules Vernes 1865 novel From the Earth to the Moon. The Lunar Module was named Eagle for the bird of the United States, the bald eagle. The Apollo 11 mission insignia was designed by Collins, who wanted a symbol for peaceful lunar landing by the United States and he chose an eagle as the symbol, put an olive branch in its beak, and drew a lunar background with the Earth in the distance. NASA officials said the talons of the eagle looked too warlike and after some discussion, All colors are natural, with blue and gold borders around the patch. When the Eisenhower dollar coin was released in 1971, the design provided the eagle for its reverse side. The design was used for the smaller Susan B
10.
Mare Tranquillitatis
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Mare Tranquillitatis is a lunar mare that sits within the Tranquillitatis basin on the Moon. The mare material within the basin consists of basalt formed in the intermediate to young age group of the Upper Imbrian epoch, the surrounding mountains are thought to be of the Lower Imbrian epoch, but the actual basin is probably Pre-Nectarian. The basin has irregular margins and lacks a defined multiple-ringed structure, palus Somni, on the northeastern rim of the mare, is filled with the basalt that spilled over from Tranquillitatis. This Mare has a bluish tint relative to the rest of the moon. The color is due to higher metal content in the basaltic soil or rocks. Unlike many other maria, there is no mass concentration, or gravitational high, mascons were identified in the center of other maria from Doppler tracking of the five Lunar Orbiter spacecraft in 1968. The gravity field was mapped at higher resolution with later orbiters such as Lunar Prospector and GRAIL, Mare Tranquillitatis was named in 1651 by astronomers Francesco Grimaldi and Giovanni Battista Riccioli in their lunar map Almagestum novum. Surveyor 5 landed in Mare Tranquillitatis on September 11,1967 and this mare was also the landing site for the first crewed landing on the Moon on July 20,1969, at 20,18 UTC. After astronauts Neil Armstrong and Buzz Aldrin made a touchdown in the Apollo 11 Lunar Module named Eagle, Armstrong told flight controllers on Earth, Houston. The landing area at 0. 8° N,23, along the periphery of the mare are several bay-shaped features that have been given names, Sinus Amoris, Sinus Asperitatis, Sinus Concordiae, and Sinus Honoris. At the left is the east side of Mare Tranquillitatis, with the craters Franz, Lyell, the bay of dark mare at left is Sinus Concordiae, with islands of older, light highland material. At right is the crater Cauchy, which lies between the Rupes Cauchy and Cauchy rille, the center photo shows the central mare with craters Vitruvius and Gardner. At the horizon are lighter highlands at the margin of the mare. The crater Jansen is visible at the edges of both the center and right photos, the right photo shows the western mare, with the craters Dawes and the large Plinius, with the Plinius Rilles in the foreground. These photos were taken within minutes of each other as the Command Module America orbited the moon, the sun elevation drops from 46 degrees at left to 30 degrees at right. Israeli psych-progressive rock band Jericho Jones recorded a song named Mare Tranquilitatas as the track of their UK album release Junkies. The band is known as The Churchills. Mare Tranquillitatis is also the name of a composition of music by composer Vangelis on his 1976 album, Sea of Tranquility is also a song by the progressive rock band Barclay James Harvest, included in their 1977 album Gone to Earth
