Adams (lunar crater)
Adams is a lunar impact crater, located in the rugged southeastern section of the Moon, near the lunar limb. It lies just to the southwest of the crater Legendre. To the northwest are the craters Hase and Petavius, to the southwest is Furnerius. To the southwest of Adams is a system of rilles designated the Rimae Hase; the longest of these rilles follows a course to the southeast. The rim of Adams is circular in form, but somewhat worn by small impact craters. There is a slight notched protrusion at the southern end of the wall; the floor is undistinguished, with no significant protrusions, only minor craterlets. Adams' name jointly honours three astronomers of that name: John Couch Adams, Walter Sydney Adams and Charles Hitchcock Adams. By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint, closest to Adams. 1996 Adams, asteroid
Abbe is a lunar impact crater, located in the southern hemisphere on the far side of the Moon. It is located just to the south of the crater Hess, lies to the east of the large walled basin Poincaré, it is named after the German physicist Ernst Abbe. The outer wall of Abbe is somewhat eroded, with small craters lying across the northwest and southwest rim crests; the interior floor is smooth, with a few tiny craterlets marking the surface. By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint, closest to Abbe. Images of Abbe crater at LPI moon atlas
Lava is molten rock generated by geothermal energy and expelled through fractures in planetary crust or in an eruption at temperatures from 700 to 1,200 °C. The structures resulting from subsequent solidification and cooling are sometimes described as lava; the molten rock is formed in the interior of some planets, including Earth, some of their satellites, though such material located below the crust is referred to by other terms. A lava flow is a moving outpouring of lava created during a non-explosive effusive eruption; when it has stopped moving, lava solidifies to form igneous rock. The term lava flow is shortened to lava. Although lava can be up to 100,000 times more viscous than water, lava can flow great distances before cooling and solidifying because of its thixotropic and shear thinning properties. Explosive eruptions produce a mixture of volcanic ash and other fragments called tephra, rather than lava flows; the word lava comes from Italian, is derived from the Latin word labes which means a fall or slide.
The first use in connection with extruded magma was in a short account written by Francesco Serao on the eruption of Vesuvius in 1737. Serao described "a flow of fiery lava" as an analogy to the flow of water and mud down the flanks of the volcano following heavy rain; the composition of all lava of the Earth's crust is dominated by silicate minerals feldspars, pyroxenes, amphiboles and quartz. Igneous rocks, which form lava flows when erupted, can be classified into three chemical types: felsic and mafic; these classes are chemical, the chemistry of lava tends to correlate with the magma temperature, its viscosity and its mode of eruption. Felsic or silicic lavas such as rhyolite and dacite form lava spines, lava domes or "coulees" and are associated with pyroclastic deposits. Most silicic lava flows are viscous, fragment as they extrude, producing blocky autobreccias; the high viscosity and strength are the result of their chemistry, high in silica, potassium and calcium, forming a polymerized liquid rich in feldspar and quartz, thus has a higher viscosity than other magma types.
Felsic magmas can erupt at temperatures as low as 650 to 750 °C. Unusually hot rhyolite lavas, may flow for distances of many tens of kilometres, such as in the Snake River Plain of the northwestern United States. Intermediate or andesitic lavas are lower in aluminium and silica, somewhat richer in magnesium and iron. Intermediate lavas form andesite domes and block lavas, may occur on steep composite volcanoes, such as in the Andes. Poorer in aluminium and silica than felsic lavas, commonly hotter, they tend to be less viscous. Greater temperatures tend to destroy polymerized bonds within the magma, promoting more fluid behaviour and a greater tendency to form phenocrysts. Higher iron and magnesium tends to manifest as a darker groundmass, occasionally amphibole or pyroxene phenocrysts. Mafic or basaltic lavas are typified by their high ferromagnesian content, erupt at temperatures in excess of 950 °C. Basaltic magma is high in iron and magnesium, has lower aluminium and silica, which taken together reduces the degree of polymerization within the melt.
Owing to the higher temperatures, viscosities can be low, although still thousands of times higher than water. The low degree of polymerization and high temperature favors chemical diffusion, so it is common to see large, well-formed phenocrysts within mafic lavas. Basalt lavas tend to produce low-profile shield volcanoes or "flood basalt fields", because the fluidal lava flows for long distances from the vent; the thickness of a basalt lava on a low slope, may be much greater than the thickness of the moving lava flow at any one time, because basalt lavas may "inflate" by supply of lava beneath a solidified crust. Most basalt lavas are of pāhoehoe types, rather than block lavas. Underwater, they can form pillow lavas, which are rather similar to entrail-type pahoehoe lavas on land. Ultramafic lavas such as komatiite and magnesian magmas that form boninite take the composition and temperatures of eruptions to the extreme. Komatiites contain over 18% magnesium oxide, are thought to have erupted at temperatures of 1,600 °C.
At this temperature there is no polymerization of the mineral compounds, creating a mobile liquid. Most if not all ultramafic lavas are no younger than the Proterozoic, with a few ultramafic magmas known from the Phanerozoic. No modern komatiite lavas are known, as the Earth's mantle has cooled too much to produce magnesian magmas; some lavas of unusual composition have erupted onto the surface of the Earth. These include: Carbonatite and natrocarbonatite lavas are known from Ol Doinyo Lengai volcano in Tanzania, the sole example of an active carbonatite volcano. Iron oxide lavas are thought to be the source of the iron ore at Kiruna, Sweden which formed during the Proterozoic. Iron oxide lavas of Pliocene age occur at the El Laco volcanic complex on the Chile-Argentina border. Iron oxide lavas are thought to be the result of immiscible separation of iron oxide magma from a parental magma of calc-alkaline or alkaline composition. Sulfur lava flows up to 250 metres 10 metres wide occur at Lastarria volcano, Chile.
They were formed by the melting of sulfur deposits at temperatures as low as 113 °C
Abbot is a small lunar impact crater that lies on the rugged ground between the Mare Fecunditatis in the south and west, the Mare Crisium to the north. It is a circular crater with a cup-shaped interior; the inner walls slope downward to the midpoint, no impacts of significant mark the interior or the rim. Abbot is named after the American astrophysicist Charles Greeley Abbot, it was designated Apollonius K before being given its name by the IAU. Apollonius itself lies to the east of the crater Abbot. LTO-62D1 Abbot — L&PI topographic map
The National Aeronautics and Space Administration is an independent agency of the United States Federal Government responsible for the civilian space program, as well as aeronautics and aerospace research. NASA was established in 1958; the new agency was to have a distinctly civilian orientation, encouraging peaceful applications in space science. Since its establishment, most US space exploration efforts have been led by NASA, including the Apollo Moon landing missions, the Skylab space station, the Space Shuttle. NASA is supporting the International Space Station and is overseeing the development of the Orion Multi-Purpose Crew Vehicle, the Space Launch System and Commercial Crew vehicles; the agency is responsible for the Launch Services Program which provides oversight of launch operations and countdown management for unmanned NASA launches. NASA science is focused on better understanding Earth through the Earth Observing System. From 1946, the National Advisory Committee for Aeronautics had been experimenting with rocket planes such as the supersonic Bell X-1.
In the early 1950s, there was challenge to launch an artificial satellite for the International Geophysical Year. An effort for this was the American Project Vanguard. After the Soviet launch of the world's first artificial satellite on October 4, 1957, the attention of the United States turned toward its own fledgling space efforts; the US Congress, alarmed by the perceived threat to national security and technological leadership, urged immediate and swift action. On January 12, 1958, NACA organized a "Special Committee on Space Technology", headed by Guyford Stever. On January 14, 1958, NACA Director Hugh Dryden published "A National Research Program for Space Technology" stating: It is of great urgency and importance to our country both from consideration of our prestige as a nation as well as military necessity that this challenge be met by an energetic program of research and development for the conquest of space... It is accordingly proposed that the scientific research be the responsibility of a national civilian agency...
NACA is capable, by rapid extension and expansion of its effort, of providing leadership in space technology. While this new federal agency would conduct all non-military space activity, the Advanced Research Projects Agency was created in February 1958 to develop space technology for military application. On July 29, 1958, Eisenhower signed the National Aeronautics and Space Act, establishing NASA; when it began operations on October 1, 1958, NASA absorbed the 43-year-old NACA intact. A NASA seal was approved by President Eisenhower in 1959. Elements of the Army Ballistic Missile Agency and the United States Naval Research Laboratory were incorporated into NASA. A significant contributor to NASA's entry into the Space Race with the Soviet Union was the technology from the German rocket program led by Wernher von Braun, now working for the Army Ballistic Missile Agency, which in turn incorporated the technology of American scientist Robert Goddard's earlier works. Earlier research efforts within the US Air Force and many of ARPA's early space programs were transferred to NASA.
In December 1958, NASA gained control of the Jet Propulsion Laboratory, a contractor facility operated by the California Institute of Technology. The agency's leader, NASA's administrator, is nominated by the President of the United States subject to approval of the US Senate, reports to him or her and serves as senior space science advisor. Though space exploration is ostensibly non-partisan, the appointee is associated with the President's political party, a new administrator is chosen when the Presidency changes parties; the only exceptions to this have been: Democrat Thomas O. Paine, acting administrator under Democrat Lyndon B. Johnson, stayed on while Republican Richard Nixon tried but failed to get one of his own choices to accept the job. Paine was confirmed by the Senate in March 1969 and served through September 1970. Republican James C. Fletcher, appointed by Nixon and confirmed in April 1971, stayed through May 1977 into the term of Democrat Jimmy Carter. Daniel Goldin was appointed by Republican George H. W. Bush and stayed through the entire administration of Democrat Bill Clinton.
Robert M. Lightfoot, Jr. associate administrator under Democrat Barack Obama, was kept on as acting administrator by Republican Donald Trump until Trump's own choice Jim Bridenstine, was confirmed in April 2018. Though the agency is independent, the survival or discontinuation of projects can depend directly on the will of the President; the first administrator was Dr. T. Keith Glennan appointed by Republican President Dwight D. Eisenhower. During his term he brought together the disparate projects in American space development research; the second administrator, James E. Webb, appointed by President John F. Kennedy, was a Democrat who first publicly served under President Harry S. Truman. In order to implement the Apollo program to achieve Kennedy's Moon la
Lunar Orbiter 4
Lunar Orbiter 4 was an unmanned U. S. spacecraft, part of the Lunar Orbiter Program, designed to orbit the Moon, after the three previous orbiters had completed the required needs for Apollo mapping and site selection. It was given a more general objective, to "perform a broad systematic photographic survey of lunar surface features in order to increase the scientific knowledge of their nature and processes, to serve as a basis for selecting sites for more detailed scientific study by subsequent orbital and landing missions", it was equipped to collect selenodetic, radiation intensity, micrometeoroid impact data. The spacecraft was placed in a cislunar trajectory and injected into an elliptical near polar high lunar orbit for data acquisition; the orbit was 2,706 by 6,111 kilometres with an inclination of 85.5 degrees and a period of 12 hours. After initial photography on May 11, 1967 problems started occurring with the camera's thermal door, not responding well to commands to open and close.
Fear that the door could become stuck in the closed position covering the camera lenses led to a decision to leave the door open. This required extra attitude control maneuvers on each orbit to prevent light leakage into the camera which would ruin the film. On May 13 it was discovered that light leakage was damaging some of the film, the door was tested and closed; some fogging of the lens was suspected due to condensation resulting from the lower temperatures. Changes in the attitude raised the temperature of the camera and eliminated the fogging. Continuing problems with the readout drive mechanism starting and stopping beginning on May 20 resulted in a decision to terminate the photographic portion of the mission on May 26. Despite problems with the readout drive the entire film was transmitted; the spacecraft acquired photographic data from May 11 to 26, 1967, readout occurred through June 1, 1967. The orbit was lowered to gather orbital data for the upcoming Lunar Orbiter 5 mission. A total of 419 high-resolution and 127 medium-resolution frames were acquired, covering 99% of the Moon's near side at resolutions from 58 to 134 metres.
Accurate data was acquired from all other experiments throughout the mission. Radiation data showed increased dosages due to solar particle events producing low energy protons; the spacecraft was used for tracking until it struck the lunar surface due to the natural decay of the orbit no than October 31, 1967, between 22–30 degrees W longitude. Lunar Orbiter Image Recovery Project Exploration of the Moon Lunar Orbiter 1 Lunar Orbiter 2 Lunar Orbiter 3 Lunar Orbiter 5 DESTINATION MOON: A history of the Lunar Orbiter Program 1976 Lunar Orbiter Photo Gallery - Mission 4 at the Lunar and Planetary Institute
Plato is a lava-filled lunar impact crater on the Moon. Its diameter is 101 km, it was named after ancient Greek philosopher Plato. It is located on the northeastern shore of the Mare Imbrium, at the western extremity of the Montes Alpes mountain range. In the mare to the south are several rises collectively named the Montes Teneriffe. To the north lies the wide stretch of the Mare Frigoris. East of the crater, among the Montes Alpes, are several rilles collectively named the Rimae Plato; the age of Plato is about 3.84 billion years, only younger than the Mare Imbrium to the south. The rim is irregular with 2-km-tall jagged peaks that project prominent shadows across the crater floor when the Sun is at a low angle. Sections of the inner wall display signs of past slumping, most notably a large triangular slide along the western side; the rim of Plato is circular. The flat floor of Plato has a low albedo, making it appear dark in comparison to the surrounding rugged terrain; the floor lacks a central peak.
However, there are a few small craterlets scattered across the floor. Plato has developed a reputation for transient lunar phenomena, including flashes of light, unusual colour patterns, areas of hazy visibility; these anomalies are a result of seeing conditions, combined with the effects of different illumination angles of the Sun. By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint, closest to Plato; the following craters have been renamed by the IAU: Plato A — See Bliss. The crater Plato is the location of an observatory in Arthur C. Clarke's novel Earthlight, of the lunar "warren" Hong Kong Luna in Robert A. Heinlein's novel The Moon Is a Harsh Mistress, of Moonbase Alpha in the science-fiction TV series Space: 1999. Crater Plato is the home crater of Matthew Looney and Maria Looney, protagonists of the Looney series of children's books set on the Moon, written by Jerome Beatty. Plato at The Moon Wiki Media related to Plato at Wikimedia Commons From LROC:Balcony Over Plato Bench Crater in Plato Scalelike Impact MeltsLunar Orbiter Photo Number IV-127-H3 Pictures of Plato on SkyTrip.de High resolution lunar overflight video by Seán Doran, based on LRO data, that passes over Plato about two thirds of the way through NASA Astronomy Picture of the Day: Moon Mare and Montes - one of the prominent features of the photo includes Plato NASA Astronomy Picture of the Day: Plato and the Lunar Alps Wood, Chuck.
"Peaks of Plato". Lunar Photo of the Day. NASA Astronomy Picture of the Day: Plato and the Lunar Alps