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Theon Junior (crater)
Theon Junior is a lunar impact crater that is located just to the west-southwest of the crater Delambre. It forms a matching pair with Theon Senior, only a couple of crater diameters to the north-northwest. The crater is circular and bowl-shaped, with a small floor at the bottom of the high, sloping interior walls. It is named for Theon of Alexandria, a 4th-century Greek astronomer and mathematician. The crater is from the Eratosthenian period, which lasted from 3.2 to 1.1 billion Billion is a word for a large number, and it has two distinct definitions: *1,000,000,000, i.e. one thousand million, or (ten to the ninth power), as defined on the short scale. This is its only current meaning in English. * 1,000,000,000,000, i.e ... years ago. It is 17 kilometers in diameter and the difference in height at its rim and its deepest part is 3,580 meters. Satellite craters By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Orbiter 4
Lunar Orbiter 4 was a robotic U.S. spacecraft, part of the Lunar Orbiter program, Lunar Orbiter Program, designed to orbit the Moon, after the three previous orbiters had completed the required needs for Project Apollo, 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, origin, and processes, and to serve as a basis for selecting sites for more detailed scientific study by subsequent orbital and landing missions". It was also equipped to collect selenodetic, radiation intensity, and micrometeoroid impact data. Mission Summary The spacecraft was placed in a Free-return trajectory, cislunar trajectory and injected into an elliptical near polar high lunar orbit for data acquisition. The orbit was with an inclination of 85.5 degrees and a period of 12 hours. After initial photography on May 11, 1967 problems started occu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theon Of Alexandria
Theon of Alexandria (; grc, Θέων ὁ Ἀλεξανδρεύς; 335 – c. 405) was a Greek scholar and mathematician who lived in Alexandria, Egypt. He edited and arranged Euclid's '' Elements'' and wrote commentaries on works by Euclid and Ptolemy. His daughter Hypatia also won fame as a mathematician. Life Little is known about the life of Theon. He made predictions and observations of solar and lunar eclipses in 364 which show he was active at that time, and he is said to have lived during the reign of Theodosius I (379–395). The ''Suda'', a tenth-century Byzantine encyclopedia, calls Theon a "man of the Mouseion".SudaTheon θ205/ref> However, both the Library of Alexandria and the original Mouseion were destroyed in the first century BC and according to classical historian Edward J. Watts, Theon was probably the head of a school called the "Mouseion", which was named in emulation of the Hellenistic Mouseion that had once included the Library of Alexa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theon Craters AS16-M-1392
Theon may refer to: * The Ancient Greek word for God or gods; see * Theon, Washington, a community in the United States * Theon Junior (crater), a lunar impact crater * Theon Senior (crater), a lunar impact crater People with the name Given name or stage name * Theon (1st century BC), literary critic and lexicographer * Theon (rhetorician) (c. 500), teacher of Damascius * Theon, vocalist for Lovex * Theon of Alexandria (c. 335 – c. 405), a Greek astronomer and mathematician * Theon of Samos, painter * Theon of Smyrna (c. 70 – c. 135), philosopher and mathematician Surname * Aelius Theon (mid to late first century A.D.), teacher of rhetorics * Alma Théon (1843–1908), clairvoyant and occultist * Max Théon (1848–1927), kabbalist and occultist See also *Theion (other) *Then (other) *Theon (other) *Thien (other) *Thiên (other) *Thoen (name) *Thone (other) Thone may refer to one of the following. * Thone River in Ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lunar Craters
Lunar craters are impact craters on Earth's Moon. The Moon's surface has many craters, all of which were formed by impacts. The International Astronomical Union currently recognizes 9,137 craters, of which 1,675 have been dated. History The word ''crater'' was adopted from the Greek word for "vessel" (, a Greek vessel used to mix wine and water). Galileo built his first telescope in late 1609, and turned it to the Moon for the first time on November 30, 1609. He discovered that, contrary to general opinion at that time, the Moon was not a perfect sphere, but had both mountains and cup-like depressions. These were named craters by Johann Hieronymus Schröter (1791), extending its previous use with volcanoes. Robert Hooke in ''Micrographia'' (1665) proposed two hypotheses for lunar crater formation: one, that the craters were caused by projectile bombardment from space, the other, that they were the products of subterranean lunar volcanism. Scientific opinion as to the origin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Crater
An impact crater is a circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact craters typically have raised rims and floors that are lower in elevation than the surrounding terrain. Lunar impact craters range from microscopic craters on lunar rocks returned by the Apollo Program and small, simple, bowl-shaped depressions in the lunar regolith to large, complex, multi-ringed impact basins. Meteor Crater is a well-known example of a small impact crater on Earth. Impact craters are the dominant geographic features on many solid Solar System objects including the Moon, Mercury, Callisto, Ganymede and most small moons and asteroids. On other planets and moons that experience more active surface geological processes, such as Earth, Venus, Europa, Io and Titan, visible impact craters are less common because they become eroded ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delambre (crater)
Delambre is a lunar impact crater that lies to the southwest of Mare Tranquillitatis, in the central highland region. To the west is the crater pair of Theon Junior and Theon Senior, the latter being more distant and located to the northwest. It is 52 kilometers in diameter and 3.5 kilometers in depth. It was named for Jean Baptiste Joseph Delambre, an 18th-century French astronomer.''Autostar Suite Astronomer Edition''. CD-ROM. Meade, April 2006. The rim of Delambre has a terraced interior, with a tiny craterlet lying along the northern rim. In the south is a low cut forming a slight notch. The crater interior has an irregular surface. It has high walls, with some peaks reaching 15,000 feet. Delambre was photographed by the uncrewed probe Ranger 8 on its descent towards Mare Tranquillitatis. Delambre is from the Upper Imbrian The Imbrian is a lunar geologic period divided into two epochs, the Early and Late. Early Imbrian In the lunar geologic timescale, the Early Imbri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theon Senior (crater)
Theon Senior is a lunar impact crater that is located to the northwest of the crater Delambre, and south of D'Arrest. It forms a matching pair with Theon Junior, about two crater diameters to the south-southeast. The satellite crater Theon Senior A can be found to the north. Theon Senior is named for Theon of Smyrna, a 1st-2nd century Greek mathematician and philosopher.''Autostar Suite Astronomer Edition''. CD-ROM. Meade, April 2006.Moore, Patrick (2001). ''On the Moon''. Sterling Publishing Co.. . This crater is circular and bowl-shaped, with only a small floor at the center of the steeply sloping interior walls. The crater appears relatively young, as it shows little sign of wear due to impacts. The crater is about 18 kilometers in diameter, and the distance from its rim to the floor is 3470 meters. Theon Senior is from the Eratosthenian The Eratosthenian period in the lunar geologic timescale runs from 3,200 million years ago to 1,100 million years ago. It is named after t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eratosthenian
The Eratosthenian period in the lunar geologic timescale runs from 3,200 million years ago to 1,100 million years ago. It is named after the crater Eratosthenes, which displays characteristics typical of craters of this age, including a surface that is not significantly eroded by subsequent impacts, but which also does not possess a ray system. The massive basaltic volcanism of the Imbrian period tapered off and ceased during this long span of lunar time. The youngest lunar lava flows identified from orbital images are tentatively placed near the end of this period. Its Earth equivalent consists of most of the Mesoarchean and Neoarchean eras (Archean eon), Paleoproterozoic and Mesoproterozoic eras ( Proterozoic eon). Examples Other than Eratosthenes itself, examples of large Eratosthenian craters on the near side of the moon include Langrenus, Macrobius, Aristoteles, Hausen, Moretus, Pythagoras, Scoresby, Bullialdus, Plutarch, and Cavalerius. On the far side, examples ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1,000,000,000
1,000,000,000 (one billion, short scale; one thousand million or one milliard, one yard, long scale) is the natural number following 999,999,999 and preceding 1,000,000,001. With a number, "billion" can be abbreviated as b, bil or bn. In standard form, it is written as 1 × 109. The metric prefix giga indicates 1,000,000,000 times the base unit. Its symbol is G. One billion years may be called an ''eon'' in astronomy or geology. Previously in British English (but not in American English), the word "billion" referred exclusively to a million millions (1,000,000,000,000). However, this is no longer common, and the word has been used to mean one thousand million (1,000,000,000) for several decades. The term ''milliard'' can also be used to refer to 1,000,000,000; whereas "milliard" is rarely used in English, variations on this name often appear in other languages. In the South Asian numbering system, it is known as 100 crore or 1 arab. 1,000,000,000 is also the cube of 1000 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambridge University Press
Cambridge University Press is the university press of the University of Cambridge. Granted letters patent by Henry VIII of England, King Henry VIII in 1534, it is the oldest university press A university press is an academic publishing house specializing in monographs and scholarly journals. Most are nonprofit organizations and an integral component of a large research university. They publish work that has been reviewed by schola ... in the world. It is also the King's Printer. Cambridge University Press is a department of the University of Cambridge and is both an academic and educational publisher. It became part of Cambridge University Press & Assessment, following a merger with Cambridge Assessment in 2021. With a global sales presence, publishing hubs, and offices in more than 40 Country, countries, it publishes over 50,000 titles by authors from over 100 countries. Its publishing includes more than 380 academic journals, monographs, reference works, school and uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Impact Craters On The Moon
Impact may refer to: * Impact (mechanics), a high force or shock (mechanics) over a short time period * Impact, Texas, a town in Taylor County, Texas, US Science and technology * Impact crater, a meteor crater caused by an impact event * Impact event, the collision of a meteoroid, asteroid or comet with Earth * Impact factor, a measure of the citations to a science or social science journal Books and magazines * ''Impact'' (novel), a 2010 novel by Douglas Preston *''Impact Press'', a former Orlando, Florida-based magazine * Impact Magazines, a former UK magazine publisher * ''Impact'' (conservative magazine), a British political magazine * ''Impact'' (British magazine), a British action film magazine * ''Impact'', a French action film magazine spun off from ''Mad Movies'' * ''Impact'' (UNESCO magazine), a former UNESCO quarterly titled ''IMPACT of science on society'' * ''Impact'' (student magazine), a student magazine for the University of Nottingham, England * ''Bathimp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
