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Phoebe (moon)
Phoebe ( ) is an irregular satellite of Saturn with a mean diameter of . It was discovered by William Henry Pickering on March 18, 1899 from photographic plates that had been taken starting on 16 August 1898 at the Boyden Station of the Carmen Alto Observatory near Arequipa, Peru, by DeLisle Stewart. It was the first satellite to be discovered photographically. Phoebe was the first target encountered upon the arrival of the '' Cassini'' spacecraft in the Saturn system in 2004, and is thus unusually well-studied for an irregular satellite of its size. ''Cassinis trajectory to Saturn and time of arrival were specifically chosen to permit this flyby. After the encounter and its insertion into orbit, ''Cassini'' did not go much beyond the orbit of Iapetus. Phoebe is roughly spherical and has a differentiated interior. It was spherical and hot early in its history and was battered out of roundness by repeated impacts. It is believed to be a captured centaur that originated in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phoebe (mythology)
In ancient Greek religion and mythology, Phoebe ( ; grc, Φοίβη, Phoíbē, associated with ''phoîbos'', "shining") was one of the first generation of Titans, who were one set of sons and daughters of Uranus and Gaia.Hesiod, ''Theogony'116-138 She was the grandmother of the sun god Apollo, the moon goddess Artemis, and the witchcraft goddess Hecate. According to myth, she was the original owner of the Oracle of Delphi before gifting it to her grandson Apollo. Her name, meaning "bright", was also given to a number of lunar goddesses like Artemis and later the Roman goddesses Luna and Diana, but Phoebe herself was not actively treated as a moon goddess on her own right in ancient mythology. Etymology Greek , feminine form of ' means "pure, bright".'' A Greek-English Lexicon'' s.vφοῖβος Another meaning is "prophet", a reference to her role in myth. Used for water and fire both, it can thus be explained as generally meaning "pure", "clear", or "bright". Family Pho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kuiper Belt
The Kuiper belt () is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune at 30 astronomical units (AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but is far larger—20 times as wide and 20–200 times as massive. Like the asteroid belt, it consists mainly of small bodies or remnants from when the Solar System formed. While many asteroids are composed primarily of rock and metal, most Kuiper belt objects are composed largely of frozen volatiles (termed "ices"), such as methane, ammonia, and water. The Kuiper belt is home to most of the objects that astronomers generally accept as dwarf planets: Orcus, Pluto, Haumea, Quaoar, and Makemake. Some of the Solar System's moons, such as Neptune's Triton and Saturn's Phoebe, may have originated in the region. The Kuiper belt was named after Dutch astronomer Gerard Kuiper, although he did not predict its existence. In 1992, minor planet (15760) Albion was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbit
In celestial mechanics, an orbit is the curved trajectory of an object such as the trajectory of a planet around a star, or of a natural satellite around a planet, or of an artificial satellite around an object or position in space such as a planet, moon, asteroid, or Lagrange point. Normally, orbit refers to a regularly repeating trajectory, although it may also refer to a non-repeating trajectory. To a close approximation, planets and satellites follow elliptic orbits, with the center of mass being orbited at a focal point of the ellipse, as described by Kepler's laws of planetary motion. For most situations, orbital motion is adequately approximated by Newtonian mechanics, which explains gravity as a force obeying an inverse-square law. However, Albert Einstein's general theory of relativity, which accounts for gravity as due to curvature of spacetime, with orbits following geodesics, provides a more accurate calculation and understanding of the exact mechanics of orbi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Regular Moon
In astronomy, a regular moon is a natural satellite following a relatively close and prograde orbit with little orbital inclination or eccentricity. They are believed to have formed in orbit about their primary, as opposed to irregular moons, which were captured. There are at least 57 regular satellites of the eight planets: one at Earth, eight at Jupiter, 23 named regular moons at Saturn (not counting hundreds or thousands of moonlets), 18 known at Uranus, and 7 small regular moons at Neptune (Neptune's largest moon Triton appears to have been captured). It is thought that Pluto's five moons and Haumea's two were formed in orbit about those dwarf planets out of debris created in giant collisions. Most regular moons are known to be tidally locked to their parent planet; the one known exception is Saturn's Hyperion, which exhibits chaotic rotation. See also *Irregular moon *Inner moon In astronomy, an inner moon or inner natural satellite is a natural satellite followin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retrograde And Prograde Motion
Retrograde motion in astronomy is, in general, orbital or rotational motion of an object in the direction opposite the rotation of its primary, that is, the central object (right figure). It may also describe other motions such as precession or nutation of an object's rotational axis. Prograde or direct motion is more normal motion in the same direction as the primary rotates. However, "retrograde" and "prograde" can also refer to an object other than the primary if so described. The direction of rotation is determined by an inertial frame of reference, such as distant fixed stars. In the Solar System, the orbits around the Sun of all planets and most other objects, except many comets, are prograde. They orbit around the Sun in the same direction as the sun rotates about its axis, which is counterclockwise when observed from above the Sun's north pole. Except for Venus and Uranus, planetary rotations around their axes are also prograde. Most natural satellites have prograde or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animation Of Phoebe Orbit Around Saturn
Animation is a method by which still figures are manipulated to appear as moving images. In traditional animation, images are drawn or painted by hand on transparent celluloid sheets to be photographed and exhibited on film. Today, most animations are made with computer-generated imagery (CGI). Computer animation can be very detailed 3D animation, while 2D computer animation (which may have the look of traditional animation) can be used for stylistic reasons, low bandwidth, or faster real-time renderings. Other common animation methods apply a stop motion technique to two- and three-dimensional objects like paper cutouts, puppets, or clay figures. A cartoon is an animated film, usually a short film, featuring an exaggerated visual style. The style takes inspiration from comic strips, often featuring anthropomorphic animals, superheroes, or the adventures of human protagonists. Especially with animals that form a natural predator/prey relationship (e.g. cats and mice ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Hawaii
A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United States, the designation is reserved for colleges that have a graduate school. The word ''university'' is derived from the Latin ''universitas magistrorum et scholarium'', which roughly means "community of teachers and scholars". The first universities were created in Europe by Catholic Church monks. The University of Bologna (''Università di Bologna''), founded in 1088, is the first university in the sense of: *Being a high degree-awarding institute. *Having independence from the ecclesiastic schools, although conducted by both clergy and non-clergy. *Using the word ''universitas'' (which was coined at its foundation). *Issuing secular and non-secular degrees: grammar, rhetoric, logic, theology, canon law, notarial law.Hunt Janin: "The university ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2005 In Science
The year 2005 in science and technology involved some significant events. Astronomy * January 5 – Eris, the most massive known dwarf planet in the Solar System, is identified by a team the Palomar Observatory in California from images taken on October 21, 2003 (discovery announced July 29, 2005). * February 23 – Astronomers announce the discovery of a galaxy, VIRGOHI21, that consists almost entirely of dark matter. * March 23 – Two independent teams report the observation of light from planets circling two different stars, using the Spitzer infrared space telescope. Both groups detect a during conjunction, when the planet is moving behind its sun's disk (occultation). * March 31 – Dwarf planet Makemake is discovered in the Kuiper belt (discovery announced July 29). * April 8 – Total solar eclipse. * May 18 – A second photograph by the Hubble Space Telescope confirms the discovery of two new moons of Pluto: Nix and Hydra. * July 20–27 – Controversy over the disco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jason
Jason ( ; ) was an ancient Greek mythological hero and leader of the Argonauts, whose quest for the Golden Fleece featured in Greek literature. He was the son of Aeson, the rightful king of Iolcos. He was married to the sorceress Medea. He was also the great-grandson of the messenger god Hermes, through his mother's side. Jason appeared in various literary works in the classical world of Greece and Rome, including the epic poem ''Argonautica'' and the tragedy ''Medea''. In the modern world, Jason has emerged as a character in various adaptations of his myths, such as the 1963 film '' Jason and the Argonauts'' and the 2000 TV miniseries of the same name. Persecution by Pelias Pelias (Aeson's half-brother) was power-hungry and sought to gain dominion over all of Thessaly. Pelias was the progeny of a union between their shared mother, Tyro ("high born Tyro"), the daughter of Salmoneus, and the sea god Poseidon. In a bitter feud, he overthrew Aeson (the rightful king), kill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planetary Nomenclature
Planetary nomenclature, like terrestrial nomenclature, is a system of uniquely identifying features on the surface of a planet or natural satellite so that the features can be easily located, described, and discussed. Since the invention of the telescope, astronomers have given names to the surface features they have discerned, especially on the Moon and Mars. To found an authority on planetary nomenclature, the International Astronomical Union (IAU) was organized in 1919 to designate and standardize names for features on Solar System bodies. How names are approved by the IAU When images are first obtained of the surface of a planet or satellite, a theme for naming features is chosen and a few important features are named, usually by members of the appropriate IAU task group (a commonly accepted planet-naming group). Later, as higher resolution images and maps become available, additional features are named at the request of investigators mapping or describing specific surfaces, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Astronomical Union
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and development through global cooperation. It was founded in 1919 and is based in Paris, France. The IAU is composed of individual members, who include both professional astronomers and junior scientists, and national members, such as professional associations, national societies, or academic institutions. Individual members are organised into divisions, committees, and working groups centered on particular subdisciplines, subjects, or initiatives. As of 2018, the Union had over 13,700 individual members, spanning 90 countries, and 82 national members. Among the key activities of the IAU is serving as a forum for scientific conferences. It sponsors nine annual symposia and holds a triannual General Assembly that sets policy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of Australia). The Moon is a planetary-mass object with a differentiated rocky body, making it a satellite planet under the geophysical definitions of the term and larger than all known dwarf planets of the Solar System. It lacks any significant atmosphere, hydrosphere, or magnetic field. Its surface gravity is about one-sixth of Earth's at , with Jupiter's moon Io being the only satellite in the Solar System known to have a higher surface gravity and density. The Moon orbits Earth at an average distance of , or about 30 times Earth's diameter. Its gravitational influence is the main driver of Earth's tides and very slowly lengthens Earth's day. The Moon's orbit around Earth has a sidereal period of 27.3 days. During each synodic period ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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