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5145 Pholus

5145 Pholus

5145 Pholus ("FOE luss") is a Centaur in an eccentric orbit, with a perihelion near the orbit of Saturn and aphelion near the orbit of Neptune. It is believed to have originated as a Kuiper belt object. It was discovered by David L. Rabinowitz, then of the University of Arizona's Spacewatch Project, and named by him after Pholus, the brother of the mythological Chiron, after which 2060 Chiron was named. Pholus was the second Centaur type asteroid to be discovered and was quickly found to be the reddest object observed to date in the Solar System, for which it has been occasionally nicknamed "Big Red". The color has been speculated to be due to organic compounds on its surface. (Wilson, et al., 1994) Unlike the first Centaur, 2060 Chiron, Pholus has shown no signs of cometary activity. The diameter of Pholus is estimated to be 185±16 km [http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1996ciss.conf...97D&db_key=AST&high=3d6ea7529520743].

References


- PMID 11539180 Pholus ja:%E3%83%95%E3%82%A9%E3%83%AB%E3%82%B9_%28%E5%B0%8F%E6%83%91%E6%98%9F%29

Centaur (planetoid)

The centaurs are a class of icy planetoids that orbit the Sun between Jupiter and Neptune, named after the mythical race of centaurs. The first centaur to be discovered, 2060 Chiron was found to display a coma upon its approach to perihelion, and is now officially classified as both a comet (95/P Chiron) and an asteroid, although it is far larger than a typical comet and there is some lingering controversy. Other centaurs are being monitored for comet-like activity. Centaurs are not in stable orbits and will eventually be removed from the solar system by the giant planets. Dynamical studies of their orbits indicate that centaurs are probably an intermediate orbital state of objects transitioning from the Kuiper Belt to the Jupiter Family of short period comets. Objects may be perturbed from the Kuiper Belt whereupon they become Neptune-crossing and interact gravitationally with that planet. They then become classed as centaurs, but their orbits are chaotic, evolving relatively rapidly as the centaur makes repeated close approaches to one or more of the outer planets. Some centaurs will evolve into Jupiter-crossing orbits whereupon their perihelia may become reduced into the inner solar system and they may be reclassified as active comets in the Jupiter Family if they display cometary activity. Centaurs will thus ultimately collide with the Sun or a planet or else they may be ejected into interstellar space after a close approach to one of the planets, particularly Jupiter. No centaur has yet been photographed up close by a spacecraft, although there is evidence that Saturn's moon Phoebe, imaged by the Cassini probe in 2004, may be a captured centaur. In addition, the Hubble Space Telescope has gleaned some information about the surface features of 8405 Asbolus. In 2010, the New Horizons spacecraft is expected to perform a distant flyby of a centaur, (83982) 2002 GO9. Well-known centaurs include:

External links


- [http://cfa-www.harvard.edu/iau/lists/Centaurs.html List of Centaurs and Scattered-Disk Objects]
- ja:ケンタウルス族 (小惑星)

Perihelion

: This article is about several astronomical terms (apogee & perigee, aphelion & perihelion, generic equivalents based on apsis, and related but rarer terms). In architecture, apsis is a synonym for apse; Apogee is also the name of a video game publisher. video game publisher In astronomy, an apsis (plural apsides "ap-si-deez") is the point of greatest or least distance of the elliptical orbit of a celestial body from its center of attraction (the center of mass of the system). The point of closest approach is called the periapsis or pericentre and the point of farthest approach is the apoapsis (Greek απο, from), apocentre or apapsis (the latter term, although etymologically more correct, is much less used). A straight line drawn through the periapsis and apoapsis is the line of apsides. This is the major axis of the ellipse, the line through the longest part of the ellipse. Related terms are used to identify the body being orbited. The most common are perigee and apogee, referring to Earth orbits, and perihelion and aphelion, referring to orbits around the Sun (Greek ἡλιος).

Formulae

We have:
- Periapsis: maximum speed v_\mathrm = \sqrt \,  at minimum distance r_\mathrm=(1-e)a\!\, (periapsis distance)
- Apoapsis: minimum speed v_\mathrm = \sqrt \,  at maximum distance r_\mathrm=(1+e)a\!\, (apoapsis distance) where one easily verifies :h = \sqrt :\epsilon=-\frac (each the same for both points, like they are for the whole orbit, in accordance with Kepler's laws of planetary motion (conservation of angular momentum) and the conservation of energy) where:
- a\!\, is the semi-major axis
- e\!\, is the eccentricity
- h\!\, is the specific relative angular momentum
- \epsilon\!\, is the specific orbital energy
- \mu\!\, is the standard gravitational parameter Properties: :e=\frac=1-\frac=\frac-1 Note that for conversion from heights above the surface to distances, the radius of the central body has to be added, and conversely. The arithmetic mean of the two distances is the semi-major axis a\!\,. The geometric mean of the two distances is the semi-minor axis b\!\,. The geometric mean of the two speeds is \sqrt, the speed corresponding to a kinetic energy which, at any position of the orbit, added to the existing kinetic energy, would allow the orbiting body to escape (the square root of the sum of the squares of the two speeds is the local escape velocity).

Terminology

Various related terms are used for other celestial objects. The '-gee', '-helion' and '-astron' and '-galacticon' forms are frequently used in the astronomical literature, while the other listed forms are occasionally used, although '-saturnium' has very rarely been used in the last 50 years. The '-gee' form is commonly (although incorrectly) used as a generic 'closest approach to planet' term instead of specifically applying to the Earth. The term peri/apomelasma was used by Geoffrey A. Landis in 1998 before peri/aponigricon appeared in the scientific literature in 2002.
(1) Properly pronounced 'affelion', although 'ap-helion' is commonly heard.
Since "peri" and "apo" are Greek, it is considered by purists more correct to use the Greek form for the body, giving forms such as '-zene' for Jupiter and '-krone' for Saturn. For Venus, the alternate form '-krition' (from Kritias, an older name for Aphrodite) has also been suggested. In the Moon's case, in practice all three forms are used, albeit very infrequently. The '-cynthion' form is, according to some, reserved for artificial bodies, whilst others reserve '-lune' for an object launched from the Moon and '-cynthion' for an object launched from elsewhere. For Jupiter, the '-jove' form is occasionally used by astronomers whilst the '-zene' form is never used, like the other pure Greek forms ('-cytherion' (Venus), '-areion' (Mars), '-hermion' (Mercury), '-krone' (Saturn), '-uranion' (Uranus), '-poseidion' (Neptune) and '-hadion' (Pluto)). The daunting prospect of having to maintain a different word for every orbitable body in the solar system (and beyond) is the main reason why the generic '-apsis' has become the almost universal norm.

See also


- Eccentric anomaly
- Elliptic orbit Category:Celestial mechanics Category:Astrodynamics ja:近地点・遠地点

Saturn (planet)

Saturn is the sixth planet from the Sun. It is a gas giant, the second-largest planet in the solar system after Jupiter. Saturn has a prominent system of rings, consisting of mostly ice particles with a smaller amount of rocky debris. It was named after the Roman god Saturn. Its symbol is a stylized representation of the god's sickle (Unicode: ♄). The Chinese, Korean, Japanese, and Vietnamese cultures refer to the planet as the earth star, 土星, based on the Five Elements.

Physical characteristics

Saturn's shape is visibly flattened at the poles and bulging at the equator (an oblate spheroid); its equatorial and polar diameters vary by almost 10% (120,536 km vs. 108,728 km). This is the result of its rapid rotation and fluid state. The other gas planets are also oblate, but to a lesser degree. Saturn is also the only one of the Solar System's planets less dense than water, with an average specific density of 0.69. This is only an average value, however; Saturn's upper atmosphere is less dense and its core is considerably more dense than water. Saturn's interior is similar to Jupiter's, having a rocky core at the center, a liquid metallic hydrogen layer above that, and a molecular hydrogen layer above that. Traces of various ices are also present. Saturn has a very hot interior, reaching 12000 K at the core, and it radiates more energy into space than it receives from the Sun. Most of the extra energy is generated by the Kelvin-Helmholtz mechanism (slow gravitational compression), but this alone may not be sufficient to explain Saturn's heat production. An additional proposed mechanism by which Saturn may generate some of its heat is the "raining out" of droplets of helium deep in Saturn's interior, the droplets of helium releasing heat by friction as they fall down through the lighter hydrogen. Kelvin-Helmholtz mechanism Saturn's atmosphere exhibits a banded pattern similar to Jupiter's (in fact, the nomenclature is the same), but Saturn's bands are much fainter and they're also much wider near the equator. Saturn's winds are among the Solar System's fastest; Voyager data indicates peak easterly winds of 500 m/s (1116 mph).(1) Saturn's finer cloud patterns were not observed until the Voyager flybys. Since then, however, Earth-based telescopy has improved to the point where regular observations can be made. Saturn's usually-bland atmosphere occasionally exhibits long-lived ovals and other features common on Jupiter; in 1990 the Hubble Space Telescope observed an enormous white cloud near Saturn's equator which was not present during the Voyager encounters and in 1994 another, smaller storm was observed. The 1990 storm was an example of a Great White Spot, a unique but short-lived Saturnian phenomenon with a roughly 30-year periodicity. Previous Great White Spots were observed in 1876, 1903, 1933, and 1960, with the 1933 storm being the most famous. The careful study of these episodes reveal interesting patterns; if it holds another storm will occur in ~2020.(2) Astronomers using infrared imaging have shown that Saturn has a warm polar vortex, and is the only planet in the solar system known to do so. (1) [http://www.solarviews.com/eng/vgrsat.htm Voyager Saturn Science Summary] (2) Patrick Moore, ed., The 1993 Yearbook of Astronomy, Mark Kidger, "The 1990 Great White Spot of Saturn", 176-215, (New York: W.W. Norton & Company, 1992).

Rotational behavior

Since Saturn does not rotate on its axis at a uniform rate, two rotation periods have been assigned to it, like in Jupiter's case: System I has a period of 10 h 14 min 00 s (844.3°/d) and encompasses the Equatorial Zone, which extends from the northern edge of the South Equatorial Belt to the southern edge of the North Equatorial Belt. All other Saturnian latitudes have been assigned a rotation period of 10 h 39 min 24 s (810.76°/d), which is System II. System III, based on radio emissions from the planet, has a period of 10 h 39 min 22.4 s (810.8°/d); because it is very close in value to System II, it has largely superseded it. While approaching Saturn in 2004, the Cassini spacecraft found that the radio rotation period of Saturn had increased slightly, to approximately 10 h 45 m 45 s (± 36 s). [http://www.nasa.gov/mission_pages/cassini/media/cassini-062804.html] The cause of the change is unknown.

Planetary rings

Saturn is probably best known for its planetary rings, which make it one of the most visually remarkable objects in the solar system.

History

The rings were first observed by Galileo Galilei in 1610 with his telescope, but he clearly did not know what to make of them. He wrote to the Grand Duke of Tuscany that "Saturn is not alone but is composed of three, which almost touch one another and never move nor change with respect to one another. They are arranged in a line parallel to the zodiac, and the middle one [Saturn itself] is about three times the size of the lateral ones [the edges of the rings]." He also described Saturn as having "ears." In 1612 the plane of the rings was oriented directly at the Earth and the rings appeared to vanish, and then in 1613 they reappeared again, further confusing Galileo. The riddle of the rings was not solved until 1655 by Christiaan Huygens, using a telescope much more powerful than the ones available to Galileo in his time. In 1675, Giovanni Domenico Cassini determined that Saturn's ring was actually composed of multiple smaller rings with gaps between them; the largest of these gaps was later named the Cassini Division.

Physical characteristics

The rings can be viewed using a quite modest modern telescope or with a good pair of binoculars. They extend from 6,630 km to 120,700 km above Saturn's equator, and are composed of silica rock, iron oxide, and ice particles ranging in size from specks of dust to the size of a small automobile. There are two main theories regarding the origin of Saturn's rings. One theory, originally proposed by Édouard Roche in the 19th century, is that the rings were once a moon of Saturn whose orbit decayed until it came close enough to be ripped apart by tidal forces (see Roche limit). A variation of this theory is that the moon disintegrated after being struck by a large comet or asteroid. The second theory is that the rings were never part of a moon, but are instead left over from the original nebular material that Saturn formed out of. This theory is not widely accepted today, since Saturn's rings are thought to be unstable over periods of millions of years and therefore of relatively recent origin. While the largest gaps in the rings, such as the Cassini division and Encke division, could be seen from Earth, the Voyager spacecrafts discovered the rings to have an intricate structure of thousands of thin gaps and ringlets. This structure is thought to arise from the gravitational pull of Saturn's many moons in several different ways. Some gaps are cleared out by the passage of tiny moonlets such as Pan, many more of which may yet be undiscovered, and some ringlets seem to be maintained by the gravitational effects of small shepherd satellites such as Prometheus and Pandora. Other gaps arise from resonances between the orbital period of particles in the gap and that of a more massive moon further out; Mimas maintains the Cassini division in this manner. Still more structure in the rings actually consists of spiral waves raised by the moons' periodic gravitational perturbations. Data from the Cassini space probe indicates that the rings of Saturn possess their own atmosphere, independent of that of the planet itself. The atmosphere is composed of molecular oxygen gas (O2) and is thought to be a product of the disintegration of water ice from the rings into its components, oxygen and hydrogen. [http://news.bbc.co.uk/1/hi/sci/tech/4640641.stm]

Dark side of the rings

Compare images from the Cassini spacecraft taken in March and October 2004, and a Pioneer 11 picture from 1979: The side of Saturn's rings that is lit by the Sun looks very different to the backlit side, which is darker overall and appears almost black in the thick B ring. From Earth, we cannot appreciate this because the Earth cannot view Saturn from an angle that displays the backlit side of the rings, and our only views of it are from spacecraft. In 2004, the Cassini spacecraft revealed the first views of the backlit side in 25 years.

Spokes of the rings

1979.]] Until 1980, the structure of the rings of Saturn was explained exclusively as the action of gravitational forces. The Voyager spacecraft found radial features in the B ring, called spokes, which could not be explained in this manner, as their persistence and rotation around the rings were not consistent with orbital mechanics. The spokes appear dark against the lit side of the rings, and light when seen against the unlit side. It is assumed that they are connected to electromagnetic interactions, as they rotate almost synchronously with the magnetosphere of Saturn. However, the precise mechanism behind the spokes is still unknown. magnetosphere.]] Twenty-five years later, Cassini observed the spokes again. They appear to be a seasonal phenomenon, disappearing in the Saturnian midwinter/midsummer and reappearing as Saturn comes closer to equinox. The spokes were not visible when Cassini arrived at Saturn in early 2004. Some scientists speculated that the spokes would not be visible again until 2007, based on models attempting to describe spoke formation. Nevertheless, the Cassini imaging team kept looking for spokes in images of the rings, and the spokes reappeared in images taken September 5, 2005.

Natural satellites

2005 Saturn has a large number of moons. The precise figure will never be certain as the orbiting chunks of ice in Saturn's rings are all technically moons, and it is difficult to draw a distinction between a large ring particle and a tiny moon. Seven of the moons are massive enough to have collapsed into a spheroid under their own gravitation. These are compared to Earth's moon in the table below. Saturn's most noteworthy moon is Titan, the only moon in the solar system to have a dense atmosphere.
Due to the tidal forces of Saturn, the moons are currently not at the same position as they were when they were first formed (for a timeline of discovery dates, see Timeline of natural satellites).

Exploration of Saturn

Timeline of natural satellites

Pioneer 11 flyby

Saturn was first visited by Pioneer 11 in September 1979. It flew within 20,000 km of the planet's cloudtops. Low-resolution images were acquired of the planet and few of its moons. Resolution was not good enough to discern surface features, however. The spacecraft also studied the rings; among the discoveries were the thin F-ring and the fact that dark gaps in the rings are bright when viewed towards the Sun, or in other words, they are not empty of material. It also measured the temperature of Titan. [http://spaceprojects.arc.nasa.gov/Space_Projects/pioneer/PN10&11.html]

Voyager flybys

In November 1980, the Voyager 1 probe visited the Saturn system. It sent back the first high-resolution images of the planet, rings, and the satellites. Surface features of various moons were seen for the first time. Voyager 1 performed a close flyby of Titan greatly increasing our knowledge of the atmosphere of the moon. However, it also proved that Titan's atmosphere is impenetrable in visible wavelengths, so no surface details were seen. The flyby also changed spacecraft's trajectory out from the plane of the solar system. Almost a year later, in August 1981, Voyager 2 continued the study of the Saturn system. More close-up images of Saturn's moons were acquired, as well as evidence of changes in the atmosphere and the rings. Unfortunately, during the flyby, the probe's camera stuck and some planned imaging was lost. Saturn's gravity was used to direct the spacecraft's trajectory towards Uranus. The probes discovered and confirmed several new satellites orbiting near or within the planet's rings. They also discovered the small Maxwell and Keeler gaps.

Cassini orbiter

On July 1, 2004, the Cassini-Huygens spacecraft performed the SOI (Saturn Orbit Insertion) maneuver and entered into orbit around Saturn. Before the SOI, Cassini had already studied the system extensively. In June 2004, it had conducted a close flyby of Phoebe sending back high-resolution images and data. The orbiter completed two Titan flybys before releasing the Huygens probe on December 25, 2004. Huygens descended onto the surface of Titan on January 14, 2005, sending a flood of data during the atmospheric descent and after the landing. As of 2005, Cassini is conducting multiple flybys of Titan and icy satellites. The primary mission ends in 2008 when the spacecraft has completed 74 orbits around the planet. :For the latest information and news releases, see [http://saturn.jpl.nasa.gov Cassini website].

Best viewing of Saturn

2008 While it is a rewarding target for observation for most of the time it is visible in the sky, Saturn and its rings are best seen when the planet is at or near opposition (the configuration of a planet when it is at an elongation of 180° and thus appears opposite the Sun in the sky.) In the opposition on January 13, 2005, Saturn appeared at its brightest until 2031, mostly due to a favourable orientation of the rings relative to the Earth. Saturn appears to the naked eye in the night sky as a bright, yellowish star varying usually between magnitude +1 and 0 and takes approximately 29 and a half years to make a complete circuit of the ecliptic against the background constellations of the zodiac. Optical aid (a large pair of binoculars or a telescope) magnifying at least 20X is required to clearly resolve Saturn's rings for most people.

Appearance

Saturn in fiction and film

Saturn is a popular setting for science fiction novels and films, although the planet tends to be used as a pretty backdrop rather than as an important part of the plot.
- In Voltaire's Micromégas (1752), the eponymous hero arrives at Saturn first (Uranus and Neptune were unknown then). Saturn's citizens are « only a thousand fathoms high », have 72 senses and live for about 15,000 years. Micromégas forms a close friendship with the secretary of the Academy of Saturn, who accompanies him to Earth.
- The unwitting adventurers in Jules Verne's Off on a Comet (1877) pass within 415,000,000 miles of Saturn while riding on a comet. The book describes Saturn as having 8 satellites and 3 rings. It contains a black and white illustration showing what night might look like from the surface of the planet. The rings are brightly illuminated by the sun, and an elliptical shadow is cast on them by the planet. The drawing shows the surface of Saturn as a rocky, desolate, solid surface.
- In H. P. Lovecraft's Cthulhu Mythos (1928–), Saturn was known as Cykranosh in the Hyperborean Era, both Tsathoggua and Atlach-Nacha came to Earth from there, and Tsathoggua's paternal uncle Hziulquoigmnzhah still resides there.
- In Isaac Asimov's short story The Martian Way (1952), Martian colonists use a chunk of ice from Saturn's rings to bring water to the dry world.
- Kurt Vonnegut's novel The Sirens of Titan (1959) is partly set on Titan, Saturn's best known moon.
- In the Star Trek universe (1966–), Saturn is used for the Starfleet Academy Flight Range.
- In Arthur C. Clarke's novel version of 2001: A Space Odyssey (1968), a spacecraft visits the Saturnian system. Clarke's later novel Imperial Earth (1976) takes place partially at a human colony on Titan.
- Douglas Trumbull's film Silent Running (1972) features an ark-like spacecraft traveling through the Saturnian system.
- In the sixth book of the Yoko Tsuno comic book series (Les Trois soleils de Vinéa, 1976), a small part of the action takes place on a Vinean space station in orbit around Saturn. Saturn's moon Titan is also briefly mentioned and depicted. Other Saturnian moons are visible but not named.
- The film Saturn 3 (1980) is mostly set on one of Saturn's moons, but also features a journey through the planet's rings.
- The science fiction anime series The Super Dimension Fortress Macross (1982–1983) has one episode that takes place in Saturn's rings, and the beginning of the movie adaptation The Super Dimension Fortress Macross: Do You Remember Love? takes place near the moon Titan and Saturn's rings.
- An episode of the cartoon series Transformers from 1985, "The God Gambit," reveals that humanoid aliens have a thriving civilization on the moon Titan. In a later episode from 1986, "Money is Everything," which takes place in the year 2006, Titan has been terraformed by humans.
- Warhammer 40,000's universe (1987) places the headquarters of the Grey Knights and Ordo Malleus in Saturn's moons, owing to their defensive capability.
- Tim Burton's film Beetlejuice (1988) is partly set on a fictional Saturn, populated by giant sandworms.
- The Citadel research and mining space station, setting of the computer game System Shock (1994), is in orbit of Saturn for most of the game.
- Stephen Baxter's novel Titan (1997) is focused on the moon Titan, but contains vivid depictions of a journey through the Saturnian system.
- In Michael McCollum's novel The Clouds of Saturn (1998), SparrowHawk pilots Larson Sands and Halley Trevanon fight against the Northern Alliance during a time when the Sun has flared out of control and boiled Earth's oceans away.
- In the sci-fi anime Cowboy Bebop (1998), in the year 2068 a war was fought on Titan.
- In the anime Bishoujo Senshi Sailor Moon, Sailor Saturn is a guardian representing the planet. Her birth is thought to bring destruction to the world, as she's known as the sailor of death and rebirth. On her forehead is the planet's symbol.
- Ben Bova's novel Saturn (2003) is about a spacecraft traveling toward the planet, although Saturn itself does not figure greatly in the story.

Saturn in various cultures

Chinese and Japanese culture designate the planet Saturn as "Earth Star." This is based on Five Elements which was traditionally used to classify natural elements. In Hebrew, Saturn is called 'Shabbathai'. Its Angel is Cassiel. Its Intelligence, or beneficial spirit, is Agiel (layga), and its spirit (darker aspect) is Zazel (lzaz). See: Kabbalah.

See also


- Saturn in astrology

External links


- [http://nssdc.gsfc.nasa.gov/planetary/factsheet/saturnfact.html NASA's Saturn fact sheet]
- [http://saturn.jpl.nasa.gov/home/index.cfm NASA's Cassini mission to Saturn]
- [http://hubblesite.org/newscenter/newsdesk/archive/releases/2001/15/image/a Change of seasons on Saturn]
- [http://www.affs.org/html/studies_on_the_rings_of_saturn.html Theoretical description of the rings of Saturn]
- [http://www.vias.org/spacetrip/saturn_1.html A Trip Into Space] Description and photos of Saturn
(moon navigator) | Saturn | Pan | ...

- zh-min-nan:Thó·-chheⁿ ko:토성 ms:Zuhal ja:土星 simple:Saturn (planet) th:ดาวเสาร์

Neptune (planet)

Neptune is the eighth, or, due to Pluto's eccentric orbit, occasionally the ninth planet farthest from the Sun, and the outermost gas giant in our solar system. Although the smallest of the gas giants, Neptune is more massive than Uranus: its stronger gravitational field has compressed it to a higher density. Faint dark rings have been detected around the blue planet, but are less substantial than those of Saturn. When these rings were discovered, it was thought that they might not be complete, but this was disproved by Voyager 2. Neptune also has 2,000 km/h winds of hydrogen, helium, and methane that gives it its blue appearance. At the time of the 1989 Voyager 2 flyby, it had in its southern hemisphere a Great Dark Spot comparable to the Great Red Spot on Jupiter. The Great Dark Spot has since disappeared. Neptune possesses nine confirmed moons, and four awaiting confirmation. Neptune's largest moon, Triton, is notable for its retrograde orbit, extreme cold (38K), and extremely tenuous (14 microbar) nitrogen/methane atmosphere. Neptune is named after the Roman god of the sea. It is represented in Unicode by a stylized version of the god's trident (Ψ). The Chinese, Korean, Japanese, and Vietnamese cultures have since named this planet sea king star, 海王星. Discovered on September 23, 1846, Neptune has been visited by only one spacecraft, Voyager 2, which flew by the planet on August 25, 1989. In 2003, there was a proposal to NASA's "Vision Missions Studies" to implement a "Neptune Orbiter with Probes" mission that does Cassini-level science without fission-based electric power or propulsion. The work is being done in conjunction with JPL and the California Institute of Technology.

Discovery

Galileo's astronomical drawings show that he had first observed Neptune on December 27, 1612, and again on January 27, 1613; on both occasions Galileo mistook Neptune for a fixed star when it appeared very close (in conjunction) to Jupiter in the night sky. Believing it to be a fixed star, he cannot be credited with its discovery. At the time Galileo first observed Neptune on December 28, 1612, it was stationary in the sky because it had just turned retrograde that very day; because it was stationary in the sky and only beginning the planet's yearly retrograde cycle, its motion was far too slight to be detected with Galileo's small telescope. Had Neptune been moving at its regular/average speed when Galileo first observed it in 1612 and 1613, he would have most likely realized that it was a planet and not a fixed star due to Neptune's relatively rapid normal motion along the ecliptic compared to the extremely slow motion of any random fixed star found in the night sky. In 1821, Alexis Bouvard published astronomical tables of the orbit of Uranus. Subsequent observations revealed substantial deviations from the tables, leading Bouvard to hypothesize some perturbing body. In 1843, John Couch Adams calculated the orbit of an eighth planet that would account for Uranus' motion. He sent his calculations to Sir George Airy, the Astronomer Royal, who asked Adams for a clarification; Adams began to draft a reply but never sent it. In 1846, Urbain Le Verrier, independently of Adams, produced his own calculations but also experienced difficulties in encouraging any enthusiasm in his compatriots. However, in the same year, John Herschel started to champion the mathematical approach and persuaded James Challis to search for the planet. After much procrastination, Challis began his reluctant search in July 1846. However, in the mean time, Le Verrier had convinced Johann Gottfried Galle to search for the planet. Though still a student at the Berlin Observatory, Heinrich d'Arrest suggested that a recently drawn chart of the sky, in the region of Le Verrier's predicted location, could be compared with the current sky to seek the displacement characteristic of a planet, as opposed to a fixed star. Neptune was discovered that very night, September 23, 1846, within 1° of where Le Verrier had predicted it to be, and about 10° from Adams' prediction. Challis later realized that he had observed the planet twice in August, failing to identify it owing to his casual approach to the work. In the aftermath of the discovery, there was much nationalistic rivalry between the French and the British over who had priority and deserved credit for the discovery. Eventually an international consensus emerged that both Le Verrier and Adams jointly deserved credit. However, the issue is now being re-evaluated by historians with the rediscovery in 1998 of the "Neptune papers" (historical documents from the Royal Greenwich Observatory), which had apparently been misappropriated by astronomer Olin Eggen for nearly three decades and were not rediscovered (in his possession) until immediately after his death. After reviewing the documents, some historians now suggest that Adams did not in fact deserve equal credit with Le Verrier.

Naming

Shortly after its discovery, Neptune was referred to simply as "the planet exterior to Uranus" or as "Le Verrier's planet." The first suggestion for a name came from Galle. He proposed the name Janus. In England, Challis put forth the name Oceanus, particularly appropriate for a seafaring people. In France, Arago suggested that the new planet be called Leverrier, a suggestion which was met with stiff resistance outside France. French almanacs promptly reintroduced the name Herschel for Uranus and Leverrier for the new planet. Meanwhile, on separate and independent occasions, Adams suggested altering the name Georgian to Uranus, while Leverrier (through the Board of Longitude) suggested Neptune for the new planet. Struve came out in favor of that name on December 29, 1846, to the Saint Petersburg Academy of Sciences. Soon Neptune became the internationally accepted nomenclature. In Roman mythology Neptune was the god of the sea, identified with the Greek Poseidon. The demand for a mythological name seemed to be in keeping with the nomenclature of the other planets all of which, except for Uranus, were named in antiquity.

Physical characteristics

Orbiting so far from the sun, Neptune receives very little heat — in fact the uppermost regions of the atmosphere are −218 °C (55 K). Because Neptune is a gas giant, there is no solid surface; as one ventures deeper and deeper inside the layers of gas, however, the temperature rises steadily. It is thought that this may be leftover heat generated by infalling matter during the planet's birth, now slowly radiating away into space. Neptune's atmosphere has the highest wind speeds in the solar system, up to 2000 km/h, thought to be powered by this flow of internal heat. The internal structure resembles that of Uranus. There is likely to be a core consisting of (molten) rock and metal, surrounded by a mixture of rock, water, ammonia, and methane. The atmosphere, extending perhaps 10 to 20 percent of the way towards the center, is mostly hydrogen and helium at high altitudes, but has increasing concentrations of methane, ammonia, and water as it approaches and finally blends into the liquid interior. The pressure at the centre of Neptune is millions of times more than that on the surface of Earth. Comparing its rotational speed to its degree of oblateness indicates that it has its mass less concentrated towards the center than does Uranus. Neptune also resembles Uranus in its magnetosphere, with a magnetic field strongly tilted relative to its rotational axis at 47° and offset at least 0.55 radii (about 13,500 kilometres) from the planet's physical center. Comparing the magnetic fields of the two planets, scientists think the extreme orientation may be characteristic of flows in the interior of the planet and not the result of Uranus' sideways orientation. rotation One difference between Neptune and Uranus is the level of meteorological activity. Uranus is visually quite bland, while Neptune's high winds come with notable weather phenomena. The Great Dark Spot, an Earth-sized dark marking resembling the Great Red Spot of Jupiter, disappeared in 1994. However, a newer image of the planet taken by the Hubble Space Telescope on November 2, 1994, revealed that a smaller storm similar to its predecessor had formed over Neptune’s Northern Hemisphere. Unique among the gas giants is the presence of high clouds casting shadows on the opaque cloud deck below.

Appearance and visibility from Earth

Neptune is never visible with the naked eye. The brightness of Neptune is between magnitudes +7.7 and +8.0, so a telescope or binoculars are required to observe it. With the use of a telescope it appears as a small blue-green disk, similar in appearance to Uranus; the blue-green colour comes from the methane in its atmosphere. With an orbital period of 165 years, Neptune will soon return to the approximate position where Galle discovered it, on three different dates. These are April 11, 2009, when it will be in prograde motion; July 17, 2009, when it will be in retrograde motion; and finally for the last time for the next 165 years, on February 7, 2010. Like all planets in the solar system beyond Earth, Neptune undergoes retrogradation at certain points during its synodic period. In addition to the start of retrogradation, other events within the synodic period include astronomical opposition, the return to prograde motion, and conjunction to the Sun.

Planetary rings

conjunction Neptune has a faint planetary ring system of unknown composition. The rings have a peculiar "clumpy" structure, the cause of which is not currently understood but which may be due to the gravitational interaction with small moons in orbit near them. Evidence that the rings are incomplete first arose in the mid-1980s, when stellar occultation experiments were found to occasionally show an extra "blink" just before or after the planet occulted the star. Images by Voyager 2 in 1989 settled the issue, when the ring system was found to contain several faint rings. The outermost ring, Adams, contains three prominent arcs now named Liberté, Egalité, and Fraternité (Liberty, Equality, and Fraternity). The existence of arcs is very difficult to understand because the laws of motion would predict that arcs spread out into a uniform ring over very short timescales. The gravitational effects of Galatea, a moon just inward from the ring, are now believed to confine the arcs. Several other rings were detected by the Voyager cameras. In addition to the narrow Adams Ring 63,000 km from the centre of Neptune, the Leverrier Ring is at 53,000 km and the broader, fainter Galle Ring is at 42,000 km. A faint outward extension to the Leverrier Ring has been named Lassell; it is bounded at its outer edge by the Arago Ring at 57,000 km. New Earth-based observations announced in 2005 appeared to show that Neptune's rings are much more unstable than previously thought. In particular, it seems that the Liberté ring might disappear in as little as one century. The new observations appear to throw our understanding of Neptune's rings into considerable confusion.

Natural satellites

Neptune has 13 known moons. The largest by far, and the only one massive enough to be spheroidal, is Triton, discovered by William Lassell just 17 days after the discovery of Neptune itself. Unlike all other large planetary moons, it has a retrograde orbit. It is close enough to Neptune to be locked into a synchronous orbit, and is slowly spiraling inward. Triton is the coldest object that has been measured in the solar system.
Neptune's second known satellite, the irregular moon Nereid, has one of the most eccentric orbits of any satellite in the solar system. From July to September 1989, Voyager 2 discovered six new Neptunian moons. Of these, the irregularly shaped Proteus is notable for being as large as a body of its density can be without being pulled into a spherical shape by its own gravity. Although the second most massive Neptunian moon, it is only one quarter of one percent of the mass of Triton. Neptune's innermost four moons, Naiad, Thalassa, Despina, and Galatea, orbit close enough to be within Neptune's rings. The next farthest out, Larissa was originally discovered in 1981 when it had blocked a star. This was attributed to ring arcs, but when Voyager 2 observed Neptune in 1989, it was found to have been caused by the moon. Five new irregular moons discovered between 2002 and 2003 were announced in 2004. :For a timeline of discovery dates, see Timeline of natural satellites

Trojan asteroids

As of 2005, there are two known Trojan asteroids of Neptune which have the same orbital period as Neptune and lie in the elongated, curved regions around the L4 and L5 Lagrangian points 60° ahead of and behind Neptune. These are and .In 2005, three more suspected Neptune Trojans were spotted: , , and . Better orbits are required before they can be truly labeled as Neptune Trojans.

Neptune in fiction and film

Neptune has been used as a reference and setting in fiction and films. The first fictional visit of Neptune, portrayed as glacial but nevertheless inhabited, occurred in Spirito gentil (1889). In Olaf Stapledon's 1930 epic novel Last and First Men, Neptune is the final home of the highly evolved human race. Samuel R. Delany's 1976 novel Triton has humanity colonizing several parts of the solar system, including Neptune's largest moon. Neptune was the intended destination of the mining ship Red Dwarf in the books based on the BBC sitcom of that name, but an accident on board sends it into deep space instead. Although used purely as a backdrop, the planet was the setting of the 1997 sci-fi/horror film Event Horizon. The planet was also the home of various alien species and characters. In H. P. Lovecraft's Cthulhu Mythos (1928), Neptune is known as "Yaksh" and is inhabited by curious fungoid creatures (Clark Ashton Smith's The Family Tree of the Gods, 1944). In the anime Bishoujo Senshi Sailor Moon (1992), Sailor Neptune is the soldier representing the planet. A Pisces, she has wavy deep green hair and her image colours represent those of Neptune. On her forehead is the symbol of Neptune, which resembles a trident, Poseidon's weapon. Her attacks represent Poseidon's ocean powers (e.g. Deep Submerge). Her talisman is the Deep Aqua Mirror, also bearing the glyph and colors of Neptune. In the animated TV series Futurama (1999-2003), Neptunians are a purple-skinned, four-armed race of humanoids that coexist peacefully with humans across the solar system. Robot Santa's base is also located on Neptune.

See also


- Planets in astrology - Neptune
- Neptune's weather

Notes


- T. R. Spilker and A. P. Ingersoll (November 9, 2004). [http://www.aas.org/publications/baas/v36n4/dps2004/252.htm Outstanding Science in the Neptune System From an Aerocaptured Vision Mission]. 36th DPS Meeting, Session 14 Future Missions.
- William Sheehan, Nicholas Kollerstrom, Craig B. Waff (December 2004). [http://www.sciam.com/article.cfm?articleID=000CA850-8EA4-119B-8EA483414B7FFE9F The Case of the Pilfered Planet - Did the British steal Neptune?] Scientific American.
- [http://articles.adsabs.harvard.edu//full/seri/AN.../0025//0000164.000.html Second report of proceedings in the Cambridge Observatory relating to the new Planet (Neptune) (1847)]. Astronomische Nachrichten, volume 25, p.309. Found at articles.adsabs.harvard.edu.
- [http://planetarynames.wr.usgs.gov/append8.html Gazetteer of Planetary Nomenclature Ring and Ring Gap Nomenclature (December 8, 2004)]. USGS - Astrogeology Research Program.
- [http://www.newscientist.com/channel/space/mg18524925.900 Neptune's rings are fading away (March 26, 2005)]. New Scientist.
- Holman, Matthew J. et. al. (August 19, 2004). [http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v430/n7002/abs/nature02832_fs.html Discovery of five irregular moons of Neptune]. Nature, p. 865 - 867.
- [http://news.bbc.co.uk/2/hi/science/nature/3578210.stm Five new moons for planet Neptune (August 18, 2004)]. BBC News.

References


- Adams, J. C., "[http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1846MNRAS...7..149A&db_key=AST&data_type=HTML&format=&high=42c888df4622238 Explanation of the observed irregularities in the motion of Uranus, on the hypothesis of disturbance by a more distant planet]", Monthly Notices of the Royal Astronomical Society, Vol. 7, p. 149, November 13, 1846.
- Airy, G. B., "[http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1846MNRAS...7..121A&db_key=AST&data_type=HTML&format=&high=42c888df4622238 Account of some circumstances historically connected with the discovery of the planet exterior to Uranus]", Monthly Notices of the Royal Astronomical Society, Vol. 7, pp. 121-144, November 13, 1846.
- Challis, J., Rev., "[http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1846MNRAS...7..145C&db_key=AST&data_type=HTML&format=&high=42c888df4622238 Account of observations at the Cambridge observatory for detecting the planet exterior to Uranus]", Monthly Notices of the Royal Astronomical Society, Vol. 7, pp. 145-149, November 13, 1846.
-
- Galle, "[http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1846MNRAS...7..153G&db_key=AST&data_type=HTML&format=&high=42c888df4622238 Account of the discovery of the planet of Le Verrier at Berlin]", Monthly Notices of the Royal Astronomical Society, Vol. 7, p. 153, November 13, 1846.
-
- Smith, Bradford A. [http://www.nasa.gov/worldbook/neptune_worldbook.html "Neptune."] World Book Online Reference Center. 2004. World Book, Inc. Accessed at nasa.gov.

External links


- [http://nssdc.gsfc.nasa.gov/planetary/factsheet/neptunefact.html NASA's Neptune fact sheet]
- [http://cfa-www.harvard.edu/iau/lists/NeptuneTrojans.html MPC's List Of Neptune Trojans]
- ko:해왕성 ms:Neptun ja:海王星 simple:Neptune (planet) th:ดาวเนปจูน zh-min-nan:Hái-ông-chheⁿ

David L. Rabinowitz

David Lincoln Rabinowitz (born 1960) is a researcher at Yale University studying the Kuiper belt and the outer solar system. Along with Michael E. Brown and Chad Trujillo he has discovered trans-Neptunian objects, among them:
- 90377 Sedna - possibly the first known inner Oort cloud object.
- 90482 Orcus
- - probably larger than Pluto
-
- On his own he has discovered one other astronomical object:
- 5145 Pholus Rabinowitz, David L. Rabinowitz, David L. Rabinowitz, David L. ja:デイヴィッド・ラビノウィッツ

University of Arizona

The University of Arizona (UA) is a land-grant and space-grant institution of higher learning located in Tucson, Arizona. The University of Arizona was the first university in the state of Arizona, founded in 1885 when the state was still a territory. In 2005, total enrollment was 37,036 students. Academically, the UA is strong in many areas, and is regarded as one of the top-ranked research universities in the U.S. Among the strongest programs at UA are optical science, astronomy and astrophysics (as the UA is awarded more NASA grants for space exploration than any other university nationally), hydrology and hydrogeology, philosophy, and anthropology. The UA also has a top tier law school, and a top 20 undergraduate business school in the U.S., public or private. Arizona is classified as a Carnegie Foundation "Doctoral/Research Universities—Extensive" university, and has excellent facilities, particularly in the medicine, science and engineering disciplines. The UA is home to Arizona's only medical school, which awards an M.D. The university receives more than $400 million USD annually in research funding, generating nearly 75 percent of the research dollars in the Arizona university system. This figure is triple the total research funds generated by Arizona State University and Northern Arizona University combined, and 26th highest in the U.S. (including public and private institutions). The university has an endowment of $348.3 million USD as of 2005. Nobel laureates on the faculty include two members of the College of Optical Sciences: Dr. Nicolaas Bloembergen (Physics, 1981) and Dr. Willis E. Lamb (Physics, 1955). Including eight Pulitzer Prize winners (alumni and faculty), the UA has more than 50 faculty as elected members of exclusive academies including Britain's Royal Society, and the American Academy of Arts and Sciences, among others. Two current UA professors were also recently named to Popular Science magazine's list of "Brilliant 10." The UA was recently awarded over $325 million USD to lead NASA's 2007 mission to Mars to explore the martian arctic. The school's Lunar and Planetary Laboratory's work in the Cassini spacecraft orbit around Saturn is greater than that of any other university globally. The UA is considered a more-selective national university, with students hailing from all states in the U.S. While nearly 72 percent of students are from Arizona, 8 percent are from California, followed by a significant student presence from Illinois, Texas, and Washington (2004). The UA has approximately 2,200 international students representing 135 countries. International students comprise approximately 6 percent of the total enrollment at UA. The current and 18th university president is Peter Likins, whose term began in 1997. President Likins will vacate his post at the conclusion of the 2005-06 academic term.

Reputation, associations and rankings

Reputation


- The Council for Aid to Education ranked the UA 12th among public universities and 24th overall in financial support and gifts. Campaign Arizona, an effort to raise over $1 billion USD for the school, exceeded that goal by $200 million a year earlier than projected.
- The National Science Foundation ranks UA 16th among public universities, and 26th among all universities nationwide in research funding.
- UA receives more NASA grants annually than the next nine top NASA-Jet Propulsion Laboratory-funded universities combined.
- UA students have been selected as Flinn, Truman, Rhodes, Goldwater, Fulbright, and National Merit scholars.
  - According to The Chronicle of Higher Education, UA is among the top 25 producers of Fulbright awards in the U.S.

Notable Associations


- UA is the only school in Arizona (and one of only 62 institutions) to belong to the Association of American Universities, an organization of top research-intensive universities in North America.
- UA is an integral member of the Association of Universities for Research in Astronomy, a consortium of institutions pursuing research in astronomy. The association operates observatories and telescopes, notably Kitt Peak National Observatory near the UA campus.

Notable rankings


- In terms of comprehensive rankings, U.S. News & World Report placed UA 45th nationally among the public institutions (top tier), and 97th overall, in the publication's 2006 Guide to Colleges 1
- In 2005, UA was ranked 73rd in the world and 47th in North America by an annual listing of the Top 500 World Universitiespublished by the Institute of Higher Education in Shanghai, China.
- The Eller College of Management's programs in Accounting, Entrepreneurship, Management Information Systems, and Marketing are ranked in the nation's top 25 by U.S. News & World Report. The Eller College undergraduate program was ranked 18th in the nation (including public and private institutions) by U.S. News & World Report in 2005, the highest ranking college in the university. The Masters in MIS programhas been ranked in the top 5 by US News and World Report since the inception of the rankings. It is one of three programs to have this distinction.
  - The Eller MBA program has ranked among the top 50 programs for 11 straight years by U.S. News & World Report. In 2005 the MBA program was ranked 40th by U.S. News & World Report. Forbes Magazine ranked the Eller MBA program 33rd overall for having the best Return on Investment (ROI), in its fourth biennial rankings of business schools 2005. The MBA program was ranked 24th by The Wall Street Journal's 2005 Interactive Regional Ranking.
- The James E. Rogers College of Law at UA is continually ranked in the top tier of law schools in the U.S., and was ranked 41st nationally by U.S. News & World Report in 2005.
- The analytical chemistry program at UA is ranked 6th nationally by U.S. News & World Report (2005).

Founding of the university

The University of Arizona was approved by the Arizona Territorial Legislature in 1885. Ironically, the city of Tucson had hoped to receive the appropriation for the state's mental hospital, which carried a sum of money slightly larger than the $25,000 allotted to the state's only university (Arizona State University was founded at the same time, but it was created as the state's normal school). Tucson, having a smaller contingent of legislators than cities like Prescott and Phoenix, was granted last priority and was awarded the university, which disappointed many city residents. With no parties willing to step forth and provide land for the new institution, the citizens of Tucson prepared to return the money to the Territorial Legislature until two gamblers and a saloon keeper decided to donate the land necessary to build the school. Classes met for the first time in 1891 with 32 students in Old Main, the first building constructed on campus, and in use still today.

Athletics

Like many large public universities in the U.S., sports are a major activity on campus, and receive a large operating budget. Arizona's athletic teams are nicknamed the Wildcats, a name derived from a 1914 football game with then California champions Occidental College, where the L.A. Times asserted that Arizona "showed the fight of wildcats." The University of Arizona participates in the NCAA's Division I-A in the Pacific Ten Conference. The men's basketball team has been one of the nation's most successful programs since Lute Olson was hired as head coach in 1983. Since then, the team has amassed 18 consecutive 20-win seasons, and reached the NCAA Tournament 21 consecutive years, which is the longest active and second-longest streak in NCAA history (University of North Carolina at Chapel Hill, 27). Lute Olson has taken the Wildcats to the Final Four of the NCAA tournament in 1988, 1994, 1997, and 2001. In 1997, Arizona defeated the University of Kentucky, the defending national champions, to win the NCAA National Championship (NCAA Men's Division I Basketball Championship). The football team began at the University of Arizona in 1899 under the nickname "Varsity" (a name kept until the 1914 season when the team earned the name "Wildcats"). The football team was notably successful in the 1990s under head coach Dick Tomey and his "Desert Swarm" defense that was characterized by tough, hard-nosed tactics. In 1993, the team had its first 10-win season and drubbed the powerhouse University of Miami Hurricanes in the Fiesta Bowl by a score of 29-0. In 1998, the team posted a school-record 12-1 season and made the Holiday Bowl in which it defeated the Nebraska Cornhuskers. Arizona ended that season ranked 3rd nationally and 2nd in several publications. The baseball team has captured three national championship titles in 1976, 1980, and 1986. Arizona baseball teams have appeared in the NCAA National Championship title series a total of six times, including 1956, 1959, 1963, 1976, 1980, and 1986 (College World Series). The Arizona softball team is among the top programs in the country and a perennial powerhouse. The softball team has won six NCAA Women's College World Series titles, in 1991, 1993, 1994, 1996, 1997, and 2001 under head coach Mike Candrea (NCAA Softball Championship). The team has appeared in the NCAA National Championship in 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 2001, and 2002, a feat second only to UCLA. Mike Candrea also led the 2004 U.S. Olympic softball team to a gold medal in Athens, Greece. The university's golf teams have also been notably successful. The men's team won a national championship in 1992 (NCAA Division I Men's Golf Championships), while the women's team won national championships in 1996 and 2000 (NCAA Women's Golf Championship). Three national championships for synchronized swimming were won in 1980, 1981, and 1984, though these championships were in the Association of Intercollegiate Athletics for Women, and not the NCAA. Although surprising to some, the University of Arizona has a strong history in ice hockey. The school's team, known as the Icecats, has won over 520 games since its inception in 1978. The Icecats defeated Penn State for the National Collegiate Club Hockey National Championship in 1985. More than 100,000 fans attend Icecats home games each year, the third largest draw in all of college hockey. A number of notable individuals have also won national championships in the NCAA. These include Amanda Beard in 2001 for swimming and Annika Sörenstam in 1991 in golf. The men's cross country has also produced two individual national titles in 1986 (Aaron Ramirez) and 1994 (Martin Keino) (NCAA Men's Cross Country Champions). The women's cross country also produced two individual national titles in 1996 and 2001 (NCAA Women's Cross Country Championship).

Rivalries

A strong academic and athletic rivalry exists between the University of Arizona and Arizona State University located in Tempe. The football rivalry game between the schools is known as the Territorial Cup and is the nation's oldest. Rivalries have also been created with other Pac-10 teams, especially University of California, Los Angeles which has provided a worthy softball rival and was Arizona's main basketball rival in the early and mid-1990s. Since that time, however, UCLA has fallen off somewhat, while Arizona has maintained its basketball prowess, appearing most recently in the Elite Eight of the 2005 NCAA tournament.

Mascot

The University mascot is an anthropomorphized wildcat named Wilbur. The identity of Wilbur is kept secret through the year as the mascot appears only in costume. In 1986, Wilbur married his longtime wildcat girlfriend, Wilma. Together, Wilbur and Wilma appear along with the cheerleading squad at most Wildcat sporting events.

Notable venues


- McKale Center, opened in 1973, is currently used by men's and women's basketball, women's gymnastics, and women's volleyball. The official capacity has changed often. The largest crowd to see a game in McKale was 15,176 in 1976 for a game against the University of New Mexico, a main rival during that period. In 2000, the floor in McKale was dubbed Lute Olson Court, for the basketball program's winningest coach. During a memorial service in 2001 for Lute's wife, Bobbi, who'd passed away after a battle with ovarian cancer, the floor was renamed Lute and Bobbi Olson Court. In addition to the playing surface, McKale Center is host to the offices of the UA athletic department. McKale Center is named after J.F. Pop McKale, who was athletic director and coach from 1914 through 1957.
- Arizona Stadium, built in 1928, seats over 56,000 patrons. It hosts American football games and has also been used for university graduations. The turf is bermuda grass, taken from the local Tucson National Golf Club. Arizona football's home record is 258-139-12. The largest crowd ever in Arizona Stadium was 59,920 in 1996 for a game against Arizona State University.
- Jerry Kindall Field at Frank Sancet Stadium hosts baseball games.
- Rita Hillenbrand Memorial Stadium hosts softball games.

Academic subdivisions

The University of Arizona's academic departments and programs are organized into colleges and schools. Typically, schools are largely independent or separately important from their parent college. In addition, not all schools are a part of a college. The university maintains a current list of colleges and schools at http://www.arizona.edu/index/colleges.php

Campus museums

For current museum hours, fees, and directions see "campus visitor's guide" in the external links.
- Much of the main campus has been designated an arboretum. Plants from around the world are labeled along a self-guided plant walk. The Krutch Cactus Garden includes the tallest Boojum tree in the state of Arizona. (The university also manages Boyce Thompson Arboretum State Park, located c. 85 miles north of the main campus.)
- Two herbaria are located on the University campus and both are referred to as "ARIZ" in the Index Herbariorum
  - The University of Arizona Herbarium - contains roughly 400,000 specimens of plants.
  - The Robert L. Gilbertson Mycological Herbarium - contains more than 40,000 specimens of fungi.
- The Arizona State Museum is the oldest anthropology museum in the American Southwest.
- The Center for Creative Photography features rotating exhibits. The permanent collection includes over 70,000 photos.
- UA Museum of Art.
- The Arizona Historical Society is located one block west of campus.
- Flandrau Science Center has exhibits, a planetarium, and a public-access telescope.

Current state of the university


- Led by Roger Angel, researchers in the Steward Observatory Mirror Lab at UA are working in concert to build the world's most advanced telescope. Known as the Giant Magellan Telescope, the instrument will produce images 10 times sharper than those from the Earth-orbiting Hubble Telescope. The telescope is set to be completed in 2016 at a cost of $500 million USD. Researchers from at least nine institutions are working to secure the funding for the project. The telescope will include seven 18-ton mirrors capable of providing clear images of volcanoes and riverbeds on Mars and mountains on the moon at a rate 40 times faster than the world's current large telescopes. The mirrors of the Giant Magellan Telescope will be built at UA and transported to a permanent mountaintop site in the Chilean Andes where the telescope will be constructed. The project will secure the already reputable astronomy program at the UA among the world's best and most innovative.
- A downturn in Arizona's economy in the 2000s, coupled with the severe impact of the September 11, 2001 attacks, led to less money being allocated by the state legislature to Arizona's universities. Academic programs were hard-hit, and the university was forced to consider extensive changes, beginning in 2002. As a result, a reorganization known as "Focused Excellence" aims to focus the mission of the university on research, graduate training, and more selective undergraduate education, in part, by eliminating and merging less popular and low-revenue academic departments. The closure of some programs, notably the innovative Arizona International College and the School of Planning, provoked widespread protest. There are plans to restrict undergraduate admission to the more academically qualified students, thus further distinguishing the university from the state's larger Arizona State University. However, efforts to improve academic performance and to encourage new research areas were not enough to prevent a number of key departures from the faculty in the early 2000s, and budgets remain restricted.
- The University of Arizona is the only remaining PAC-10 conference school to not award plus and minus grades for courses. Currently, grades are given on a strict 4-point scale with "A" worth 4, "B" worth 3, "C" worth 2, "D" worth 1 and "E" worth zero points. This creates demands by students on academic staff to award "A"s and "B" grades, so that their overall grade point averages do not suffer. Discussions with students and faculty may lead the UA toward using a plus-minus grading system in the future. Administrators say that the change could occur as early as Fall 2006.
- Uncertainty currently surrounds the future of common commencement ceremonies for the entire student body. Critics of the large ceremony argue that the event has become marred by misbehavior of graduates; the administration has vowed to cancel undergraduate commencement in favor of individual college convocations if behavior does not improve. Partially at issue is the tradition in which graduates fling tortillas into the air (in a manner similar to throwing mortarboards) during the ceremony. Critics of this behavior argue it is disruptive, potentially dangerous, offensive to Mexican-Americans, and insensitive to the plight of the hungry and needy. Proponents of tortilla throwing argue it is a harmless and fun tradition. The future of commencement ceremonies at the University of Arizona will remain uncertain pending the decision of the university administration.

Recognized fraternities and sororities of the Greek System

There are currently (2005) 44 fraternity and sorority chapters that are recognized by the University of Arizona. As of 2005, approximately 7 percent of male UA students were members of campus fraternities, and 11 percent of female students were members of sororities. The fraternities and sororities are governed by 3 governing councils. The Interfraternity Council (IFC) represents 20 fraternities, the National Pan-Hellenic Council (NPHC) represents 6 historically African-American fraternities and sororities, and the Panhellenic Association (PHC) represents 18 sororities. The university maintains a full list of recognized fraternities and sororities as well as a map that highlights the locations of fraternity and sorority houses at http://www.union.arizona.edu/csil/greek/chapters/index.php

Recognized student clubs and organizations

A new and expansive Student Union building , opened in 2003 as the largest student union in the U.S. not affiliated with a hotel. The University of Arizona is home to more than 500 philanthropic, multi-cultural, social, athletic, academic, and student clubs and campus organizations. A listing is found at Center For Student Involvement and Leadership (CSIL) through the Student Union. CSIL also houses the Arizona Blue Chip Program one of the largest collegiate-level leadership development programs in the United States, with over 500 active students at any one time throughout the 4 years of the program. Blue Chip was founded in 1999 and has become so successful that an international partnership has been formed with the Univerity of Wollongong, in Wollongong, Australia where a sister program, the Black Opal Leadership Development Program began in February, 2005. Structure, curriculum, students and even staff are exchanged between the two institutions in a unique international leadership development initiative. The large size of the university and a generally student-friendly administration provides for an environment where many diverse and unique clubs can thrive. Through funding from the CSIL and the Associated Students of the University of Arizona, clubs are given the resources and encouragement to explore unusual interests.

Student government representation

The students at the University of Arizona have, since 1917, been represented by the Associated Students of the University of Arizona, or ASUA. Representation is elected by the students every year (usually in March).

Miscellany


- The University of Arizona is called Arizona nałtsoos ízisgo baa ótad in Western Apache, a language spoken in Arizona.
- In the 1974, the University of Arizona received $5.5 million USD from the Arizona state legislature to renovate its football stadium. A provision of this legislation (ARS 15-1630) prohibited the University of Arizona Medical Center from performing abortions (unless the mother's life is in jeopardy) or teaching its medical students abortion procedures. This legislation is still in effect, and could potentially impact every public medical school in Arizona, making Arizona the only state which prohibits the teaching of abortion in public universities. To address this issue, Planned Parenthood implemented a rotation for obstetrics and gynecology residents to receive abortion training. Interested residents and medical students have the ability to utilize such resources to study the medical procedure of abortion. Second and third year medical students have both scheduled and elective time available to pursue such supplemental training.
- On April 24, 2005, an article by John Merrow entitled The Undergraduate Experience: Survival of the Fittest appeared in the New York Times. The article presented the disadvantages that some freshman and poorly performing students face at large educational institutions such as the University of Arizona. The University of Arizona administration has responded to the negative publicity of the article on the grounds that the article does not accurately depict the typical experience of most university students. The article takes exception to the University's size and population by criticizing the admission of 83 percent of applicants to the University. The article also criticizes large class sizes and resulting virtual anonymity of the students in these classes. In contrast to the picture presented by the New York Times article, the University of Arizona admissions office website reports that less than 4 percent of classes are larger than 100 students and the average class size is 29.
- The University of Arizona marching band, named The Pride of Arizona, played at the halftime of the first Super Bowl.
- The film Revenge of the Nerds (1984) was filmed at the University of Arizona. In the movie, the Alpha Beta "jock" house is the real-life home to the UA chapter of the Alpha Gamma Rho Fraternity.
- In the 1994 film Speed, Keanu Reeves responds to Sandra Bullock’s University of Arizona t-shirt by saying, "Arizona Wildcats...good football team."
- The current school colors are cardinal red and navy blue. Before 1900, the colors were sage green and silver. The switch was made when a lucrative discount on red and blue jerseys became available.
- The bell housed on the USS Arizona was one of the two bells rescued from the ship after the attack on Pearl Harbor and has a permanent home in the clock tower of the Student Union Memorial Center on campus. The bell first arrived on campus in July 1946. The bell is rung seven times on the third Wednesday of every month at 12:07 p.m. to honor the achievements of the UA, as well as after football victories over all schools located outside of Arizona.
- Arizona's first mascot was a real desert bobcat named "Rufus Arizona", introduced in 1915.
- At the beginning of each school year, freshmen repaint the "A" on "A" Mountain, and for more than 100 years the "A" remains a Tucson and Wildcat landmark.
- Spring Fling is the largest student-run carnival in the U.S. and has been held annually by UA students since 1975.
- In 1952 Jack K. Lee, an applicant for the UA's band directorship, departed Tucson by air following an interview with UA administration. From his airplane window, Lee observed the huge letters on the roof of the UA gymnasium reading "BEAR DOWN." Inspired, Lee scribbled down the music and lyrics to an up-tempo song. By the time his plane landed, he had virtually finished it. A few weeks later Lee was named the UA band director, and in September 1952, the UA band performed "Bear Down, Arizona!" in public for the first time. Soon thereafter, "Bear Down, Arizona!" became accepted as UA's fight song. (Bear Down)
- The Berger Memorial Fountain at the west entrance of Old Main honors the UA students who lost their lives in World War I, and dates back to 1919.
- The first sport to bring national recognition to UA was Polo. The 1924 UA Polo Team captured the Western Collegiate Championship, and traveled to the east coast to present U.S. President Calvin Coolidge with a cowboy hat. The UA Polo team faced Princeton University for the intercollegiate title and lost 6-2 and 8-0. With the onset of World War II, the UA was unable to continue sponsoring a Polo team.

Notable alumni and faculty

With an established history, strong academic programs, and a significant tradition in athletics, the University of Arizona has been distinguished by a number of notable individuals. Notable alumni include a former U.S. Secretary of the Interior, the U.S. Surgeon General, the creator of the television series "Sesame Street" and founder of the Children's Television Workshop, the owner of the Los Angeles Angels of Anaheim Major League Baseball team, and several NASA astronauts.

External links


- University home page: [http://www.arizona.edu www.arizona.edu]
- Official UA athletics site: [http://www.arizonaathletics.com www.arizonaathletics.com]
- Campus newspaper: [http://wildcat.arizona.edu wildcat.arizona.edu]
- Campus visitor's guide: [http://www.arizona.edu/future/visiting.php Visitor's guide]
- University webcam: [http://www.cs.arizona.edu/webcam/ www.cs.arizona.edu/camera/] (with archives)
- [http://maps.google.com/maps?q=tucson&ll=32.231762,-110.950584&spn=0.010750,0.020878&t=k&hl=en Satellite image of campus] (zoomable, from maps.google.com)

Notes

# UA Highlights 2004-05 # # # # # # # # # # # # # # Category:University of Arizona Category:Arizona botanical gardens Arizona, University of Arizona Arizona Category:Tucson, Arizona Arizona, University of Arizona Arizona, University of ja:アリゾナ大学

Pholus

:In astronomy, 5145 Pholus is the name of a Centaur (planetoid) planetoid discovered in 1992 by David L. Rabinowitz. ---- In Greek mythology, Pholus was a wise centaur and friend of Herakles who lived in a cave on or near Mount Pelion. The differing accounts vary in details, but each story contains the following elements: Herakles visited his cave sometime before or after the completion of his fourth Labor, the capture of the Erymanthian Boar. When Herakles drank from a jar of wine in the possession of Pholus, the neighboring centaurs smelled its fragrant odor and, driven characteristically mad, charged into the cave. The majority were slain by Herakles, and the rest were chased to another location (in a work attributed to Apollodorus, Cape Meleia) where the peaceful centaur Chiron was accidentally wounded by the arrows of Herakles which were soaked in the venomous blood of the Lernaean Hydra. In most accounts, Chiron surrendered his immortality to be free from the agony of the poison. While this persuit and second combat was occurring, Pholus, back in his cave, accidentally wounded himself with one of the venomous arrows while he was either marveling at how such a small thing could kill a centaur (Apollodorus) or preparing the corpses for burial (Diodoros). He died quickly as a result of the poison's outrageous virulence and was found by Herakles. Much later, authors like Hyginus (in his De Astronomia) became confused with these details since Chiron and Pholus, both being the only civilized centaurs in Greek myth, died in the same story. Consequently, his writings in places exhibit a conflation of details as a result of his typical inaccuracy. In the Divine Comedy Pholus is found with the other centaurs patrolling the banks of the river Phlegethon in the seventh circle of Hell.

Pholus, Chiron, and the other Centaurs

It is well known that Chiron, the famously civilized centaur, had origins which differed from those of the other centaurs. Chiron was the son of Cronus and a minor goddess Philyra, which accounted for his exceptional intelligence and honor, whereas the other centaurs were bestial and brutal, being the descendents of the unholy rape of a minor cloud-goddess by the mortal king Ixion. Where Chiron was immortal and could died only voluntarily, the other centaurs were mortal like men and animals. Pholus, like Chiron, was civilized, and indeed in art sometimes shared the "human-centaur" form in which Chiron was usually depicted (that is, he was a man from head to toe, but with the center and hindparts of a horse attached to his buttocks). This form was of course used to differentiate Chiron and Pholus from all other centaurs, who were mostly represented as men only from the head to the waist, and therefore more animal-like. To further account for the unsually civil behavior of Pholus, Apollodorus wrote that his parents were Silenus and one of the Meliae, thus differentiating him genealogically from the other centaurs, as Chiron was known to be. This different parentage apparently did not carry with it immortality, however, and Pholus died just as the other centaurs. Category:Centaurs Category:Characters in the Divine Comedy

Sources

Gantz, Timothy. Early Greek Myth: A Guide to Literary and Artistic Sources. ja:ポロス

Chiron

:This article is about the Greek mythological character. For other uses, see Chiron (disambiguation). In Greek mythology, Chiron ("hand") — sometimes spelled Cheiron or Kiron — was held as the superlative centaur over his brethren. Like the satyrs, centaurs were notorious for being overly indulgent drinkers and carousers, given to violence when intoxicated, and generally uncultured. Chiron, by contrast, was intelligent, civilized and kind. Sired by Cronus when he had taken the form of a horse and impregnated the nymph, Philyra, Chiron came from a different lineage than other centaurs. He was the father of Ocyrrhoe with the nymph Chariklo and lived on Mount Pelion (or Pilion). A great healer, astrologer, and respected oracle, Chiron was most revered as a teacher and tutored Asclepius, Theseus, Achilles, Jason and Heracles. He had the gift of guiding his pupils to uncovering their highest potential and discovering their destiny. When the centaurs drank and partied themselves to extinction, Chiron became the last remaining centaur. His nobility is further reflected in the story of his death as Chiron sacrificed his life, allowing humanity to obtain the use of fire. Being the son of Cronus, a titan, he was therefore immortal and so could not die. So it was left to Heracles to arrange a bargain with Zeus to exchange Chiron's immortality for the life of Prometheus who had been chained to a rock and left to die for his transgressions. Chiron had been poisoned with an arrow belonging to Heracles that had been treated with the blood of the Hydra (see Lernaean Hydra) (in other versions, poison Chiron had given to the hero when he had been under the honorable centaur’s tutelage). This had taken place during the visit of Heracles to the cave of Pholus on Mount Pelion in Thessaly when he visited his friend during his fourth labour in defeating the Erymanthian Boar. While they were at supper, Heracles asked for some wine to accompany his meal. Pholus, who ate his food raw, was taken aback. He had been given a vessel of sacred wine by Dionysus sometime earlier, to be kept in trust for the rest of the centaurs until the right time for its opening. At Heracles's prompting, Pholus was forced to produce the vessel of sacred wine. The hero, gasping for wine, grabbed it from him and forced it open. Thereupon the vapours of the sacred wine wafted out of the cave and intoxicated the wild centaurs, led by Nessus, who had gathered outside. They attacked the cave with stones, rocks and fir trees. Hercules was forced to shoot many arrows (poisoned, of course, with the blood of the Hydra) to drive them back. During this assault, Chiron was hit in the thigh by one of the poisoned arrows. After the centaurs had fled, Pholus emerged from the cave to observe the destruction. Being of a philosophical frame of mind, he pulled one of the arrows from the body of a dead centaur and wondered how could such a little thing as an arrow have caused so much death and destruction? In that instant, he let slip the arrow from his hand and it dropped and hit him in the foot, killing him instantly. Ironically, Chiron, the master of the healing arts, could not heal himself, so he willingly gave up his immortality and was placed in the sky as the constellation Centaurus. Chiron saved the life of Peleus when Acastus trie