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Aegaeon (moon)
Aegaeon , or (provisional designation ), is a natural satellite of Saturn. It is thought to be similarly smooth as Methone. It orbits between Janus and Mimas within Saturn's G Ring. Discovery and naming Images of Aegaeon were taken by '' Cassini'' on 15 August 2008, and its discovery was announced on 3 March 2009 by Carolyn Porco of the Cassini Imaging Science Team using the provisional designation . Aegaeon was named after one of the hekatonkheires on 5 May 2009. Orbit Aegaeon orbits within the bright segment of Saturn's G Ring, and is probably a major source of the ring. , CICLOPS, 29 May 2009 Debris knocked off Aegaeon forms a bright arc near the inner edge, which in turn spreads to form the rest of the ring. Aegaeon orbits in a 7:6 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aegaeon (mythology)
In Greek mythology, Aegaeon ( grc-gre, Αἰγαίων, Aigaíōn, goatish", "stormy", " Aegean) may refer to the following figures: * Aegaeon also called Briareus, one of the Hecatonchires. * Aegaeon, one of the Gigantes. *Aegaeon, an Arcadian prince as one of the 50 sons of the impious King Lycaon either by the naiad Cyllene, Nonacris or by unknown woman. He and his brothers were the most nefarious and carefree of all people. To test them, Zeus visited them in the form of a peasant. These brothers mixed the entrails of a child into the god's meal, whereupon the enraged Zeus threw the meal over the table. Aegaeon was killed, along with his brothers and their father, by a lightning bolt of the god.Apollodorus3.8.1/ref> Notes References * Apollodorus, ''The Library'' with an English Translation by Sir James George Frazer, F.B.A., F.R.S. in 2 Volumes, Cambridge, MA, Harvard University Press; London, William Heinemann Ltd. 1921. Online version at the Perseus Digital Library.< ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Janus (moon)
Janus is an inner satellite of Saturn. It is also known as Saturn X. It is named after the mythological Janus. History Discovery Janus was identified by Audouin Dollfus on 15 December 1966 and given the temporary designation . Previously, had photographed Janus on 29 October 1966 without realising it. On 18 December, Richard Walker observed an object in the same orbit as Janus, but whose position could not be reconciled with the previous observations. Twelve years later, in October 1978, Stephen M. Larson and John W. Fountain realised that the 1966 observations were best explained by two distinct objects (Janus and Epimetheus) sharing very similar orbits, Walker is now credited with the discovery of Epimetheus. ''Voyager 1'' confirmed this orbital configuration in 1980. (See co-orbital moon for a more detailed description of their unique arrangement.) Observational history Janus was observed on subsequent occasions and given different provisional designations. ''Pioneer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moons Of Saturn
The moons of Saturn are numerous and diverse, ranging from tiny moonlets only tens of meters across to enormous Titan (moon), Titan, which is larger than the planet Mercury (planet), Mercury. Saturn has 83 natural satellite, moons with confirmed orbits that are not embedded in its Rings of Saturn, rings—of which only 13 have diameters greater than 50 kilometers—as well as dense rings that contain millions of embedded moonlets and innumerable smaller ring particles. Seven Saturnian moons are large enough to have collapsed into a relaxed, ellipsoidal shape, though only one or two of those, Titan and possibly Rhea (moon), Rhea, are currently in hydrostatic equilibrium. Particularly notable among Saturn's moons are Titan, the second-List of natural satellites, largest moon in the Solar System (after Jupiter's Ganymede (moon), Ganymede), with a Atmosphere of Titan#Composition, nitrogen-rich Earth-like Atmosphere of Titan, atmosphere and a landscape featuring dry river networks and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eccentricity (orbit)
In astrodynamics, the orbital eccentricity of an astronomical object is a dimensionless parameter that determines the amount by which its orbit around another body deviates from a perfect circle. A value of 0 is a circular orbit, values between 0 and 1 form an elliptic orbit, 1 is a parabolic escape orbit (or capture orbit), and greater than 1 is a hyperbola. The term derives its name from the parameters of conic sections, as every Kepler orbit is a conic section. It is normally used for the isolated two-body problem, but extensions exist for objects following a rosette orbit through the Galaxy. Definition In a two-body problem with inverse-square-law force, every orbit is a Kepler orbit. The eccentricity of this Kepler orbit is a non-negative number that defines its shape. The eccentricity may take the following values: * circular orbit: ''e'' = 0 * elliptic orbit: 0 < ''e'' < 1 * [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inclination
Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a Plane of reference, reference plane and the orbital plane or Axis of rotation, axis of direction of the orbiting object. For a satellite orbiting the Earth directly above the Equator, the plane of the satellite's orbit is the same as the Earth's equatorial plane, and the satellite's orbital inclination is 0°. The general case for a circular orbit is that it is tilted, spending half an orbit over the northern hemisphere and half over the southern. If the orbit swung between 20° north latitude and 20° south latitude, then its orbital inclination would be 20°. Orbits The inclination is one of the six orbital elements describing the shape and orientation of a celestial orbit. It is the angle between the orbital plane and the plane of reference, normally stated in degree (angle), degrees. For a satellite orbiting a planet, the plane of reference is usually ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mean Longitude
Mean longitude is the ecliptic longitude at which an orbiting body could be found if its orbit were circular and free of perturbations. While nominally a simple longitude, in practice the mean longitude does not correspond to any one physical angle. Definition * Define a reference direction, ♈︎, along the ecliptic. Typically, this is the direction of the March equinox. At this point, ecliptic longitude is 0°. * The body's orbit is generally inclined to the ecliptic, therefore define the angular distance from ♈︎ to the place where the orbit crosses the ecliptic from south to north as the '' longitude of the ascending node'', ''Ω''. * Define the angular distance along the plane of the orbit from the ascending node to the pericenter as the '' argument of the pericenter'', ''ω''. * Define the '' mean anomaly'', ''M'', as the angular distance from the pericenter which the body would have if it moved in a circular orbit, in the same orbital period as the actual body in its ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semi-major Axis
In geometry, the major axis of an ellipse is its longest diameter: a line segment that runs through the center and both foci, with ends at the two most widely separated points of the perimeter. The semi-major axis (major semiaxis) is the longest semidiameter or one half of the major axis, and thus runs from the centre, through a focus, and to the perimeter. The semi-minor axis (minor semiaxis) of an ellipse or hyperbola is a line segment that is at right angles with the semi-major axis and has one end at the center of the conic section. For the special case of a circle, the lengths of the semi-axes are both equal to the radius of the circle. The length of the semi-major axis of an ellipse is related to the semi-minor axis's length through the eccentricity and the semi-latus rectum \ell, as follows: The semi-major axis of a hyperbola is, depending on the convention, plus or minus one half of the distance between the two branches. Thus it is the distance from the center ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Resonance
In celestial mechanics, orbital resonance occurs when orbiting bodies exert regular, periodic gravitational influence on each other, usually because their orbital periods are related by a ratio of small integers. Most commonly, this relationship is found between a pair of objects (binary resonance). The physical principle behind orbital resonance is similar in concept to pushing a child on a swing, whereby the orbit and the swing both have a natural frequency, and the body doing the "pushing" will act in periodic repetition to have a cumulative effect on the motion. Orbital resonances greatly enhance the mutual gravitational influence of the bodies (i.e., their ability to alter or constrain each other's orbits). In most cases, this results in an ''unstable'' interaction, in which the bodies exchange momentum and shift orbits until the resonance no longer exists. Under some circumstances, a resonant system can be self-correcting and thus stable. Examples are the 1:2:4 resonance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hekatonkheires
In Greek mythology, the Hecatoncheires ( grc-gre, Ἑκατόγχειρες, , Hundred-Handed Ones), or Hundred-Handers, also called the Centimanes, (; la, Centimani), named Cottus, Briareus (or Aegaeon (mythology), Aegaeon) and Gyges (or Gyes), were three monstrous giants, of enormous size and strength, each with fifty heads and one hundred arms. In the standard tradition they were the offspring of Uranus (mythology), Uranus (Sky) and of Gaia (Earth), and helped Zeus and the Twelve Olympians, Olympians to overthrow the Titans in the Titanomachy. Names The three Hundred-Handers were named Cottus, Briareus and Gyges. Cottus (''Κόττος'') is a common Thracian name, and is perhaps related to the name of the Thracian goddess Kotys. The name Briareus (''Βριάρεως'') was probably formed from the Greek ''βριαρός'' meaning "strong". Hesiod's ''Theogony'' also calls him "Obriareus". The name Gyges is possibly related to the mythical Attica, Attic king Ogyges (''Ὠγύ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mimas (moon)
Mimas , also designated Saturn I, is a moon of Saturn discovered in 1789 by William Herschel. It is named after Mimas, a son of Gaia in Greek mythology. With a diameter of , it is the smallest astronomical body that is known to still be rounded in shape because of self-gravitation. However, Mimas is not actually in hydrostatic equilibrium for its current rotation. Discovery Mimas was discovered by the astronomer William Herschel on 17 September 1789. He recorded his discovery as follows: "I continued my observations constantly, whenever the weather would permit; and the great light of the forty-feet speculum was now of so much use, that I also, on the 17th of September, detected the seventh satellite, when it was at its greatest preceding elongation." The 40-foot telescope was a metal mirror reflecting telescope built by Herschel, with a aperture. The 40 feet refers to the length of the focus, not the aperture diameter as more common with modern telescopes. Name Mima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Scientist
''New Scientist'' is a magazine covering all aspects of science and technology. Based in London, it publishes weekly English-language editions in the United Kingdom, the United States and Australia. An editorially separate organisation publishes a monthly Dutch-language edition. First published on 22 November 1956, ''New Scientist'' has been available in online form since 1996. Sold in retail outlets (paper edition) and on subscription (paper and/or online), the magazine covers news, features, reviews and commentary on science, technology and their implications. ''New Scientist'' also publishes speculative articles, ranging from the technical to the philosophical. ''New Scientist'' was acquired by Daily Mail and General Trust (DMGT) in March 2021. History Ownership The magazine was founded in 1956 by Tom Margerison, Max Raison and Nicholas Harrison as ''The New Scientist'', with Issue 1 on 22 November 1956, priced at one shilling (a twentieth of a pound in pre-decimal UK cu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cassini–Huygens
''Cassini–Huygens'' ( ), commonly called ''Cassini'', was a space research, space-research mission by NASA, the European Space Agency (ESA), and the Italian Space Agency (ASI) to send a space probe to study the planet Saturn and its system, including its Rings of Saturn, rings and Moons of Saturn, natural satellites. The Large Strategic Science Missions, Flagship-class robotic spacecraft comprised both NASA's ''Cassini'' space probe and ESA's Huygens (spacecraft), ''Huygens'' lander (spacecraft), lander, which landed on Saturn's largest moon, Titan (moon), Titan. ''Cassini'' was the fourth space probe to visit Saturn and the first to enter its orbit, where it stayed from 2004 to 2017. The two craft took their names from the astronomers Giovanni Domenico Cassini, Giovanni Cassini and Christiaan Huygens. Launched aboard a Titan IV, Titan IVB/Centaur on October 15, 1997, ''Cassini'' was active in space for nearly 20 years, with 13 years spent orbiting Saturn and studying the pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
