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Rings Of Neptune
The rings of Neptune consist primarily of five principal rings. They were first discovered (as "arcs") by simultaneous observations of a stellar occultation on 22 July 1984 by André Brahic's and William B. Hubbard's teams at La Silla Observatory (ESO) and at Cerro Tololo Interamerican Observatory in Chile. They were eventually imaged in 1989 by the ''Voyager 2'' spacecraft. At their densest, they are comparable to the less dense portions of Saturn's main rings such as the C ring and the Cassini Division, but much of Neptune's ring system is quite tenuous, faint and dusty, more closely resembling the rings of Jupiter. Neptune's rings are named after astronomers who contributed important work on the planet: Galle, Le Verrier, Lassell, Arago, and Adams. Neptune also has a faint unnamed ring coincident with the orbit of the moon Galatea. Three other moons orbit between the rings: Naiad, Thalassa and Despina. The rings of Neptune are made of extremely dark material, likely or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neptunian Rings Scheme 2
Neptune was discovered in 1846 and has only made occasional appearances in fiction since then. The first time it was mentioned, then called "Leverrier's planet", was in the 1848 novel '' The Triumphs of Woman'' by Charles Rowcroft where an inhabitant of the planet visits Earth. The earliest stories where Neptune itself directly appears as a setting, such as the 1930s works " The Monsters of Neptune" by Henrik Dahl Juve and ''Last and First Men'' by Olaf Stapledon, portray it as a rocky planet rather than as having its actual gaseous composition; in the latter, it becomes humanity's refuge in the far future when the Sun expands. Later works rectified this error, with Alexei Panshin's 1969 short story " One Sunday in Neptune" depicting a voyage into Neptune's atmosphere and Alex Irvine's 2003 story " Shepherded by Galatea" featuring resource extraction in the atmosphere. In the 1969 novel '' Macroscope'' by Piers Anthony, Neptune is converted to a world ship. Neptune's largest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Naiad (moon)
Naiad , (also known as Neptune III and previously designated as S/1989 N 6) named after the naiads of Greek legend, is the innermost satellite of Neptune and the nearest to the center of any gas giant with moons with a distance of 48,224 km from the planet's center. Its orbital period is less than a Neptunian day, resulting in tidal dissipation that will cause its orbit to decay. Eventually it will either crash into Neptune's atmosphere or break up to become a new ring. History Naiad was discovered sometime before mid-September 1989 from the images taken by the ''Voyager 2'' probe. The last moon to be discovered during the flyby, it was designated S/1989 N 6. The discovery was announced on 29 September 1989, in the IAU Circular No. 4867, and mentions "25 frames taken over 11 days", implying a discovery date of sometime before 18 September. The name was given on 16 September 1991. Physical characteristics Naiad is irregularly shaped. It is likely that it is a ru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artifact (observational)
In natural science and signal processing, an artifact or artefact is any error in the perception or representation of any information introduced by the involved equipment or technique(s). Computer science In ''computer science'', digital artifacts are anomalies introduced into digital signals as a result of digital signal processing. Microscopy In '' microscopy'', visual artifacts are sometimes introduced during the processing of samples into slide form. Econometrics In ''econometrics'', which trades on computing relationships between related variables, an artifact is a spurious finding, such as one based on either a faulty choice of variables or an over-extension of the computed relationship. Such an artifact may be called a ''statistical artifact''. For instance, imagine a hypothetical finding that presidential approval rating is approximately equal to twice the percentage of citizens making more than $50,000 annually; if 60% of citizens make more than $50,000 annually, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triton (moon)
Triton is the largest natural satellite of the planet Neptune, and was the first Neptunian moon to be discovered, on October 10, 1846, by English astronomer William Lassell. It is the only large moon in the Solar System with a retrograde orbit, an orbit in the direction opposite to its planet's rotation. Because of its retrograde orbit and composition similar to Pluto, Triton is thought to have been a dwarf planet, captured from the Kuiper belt. At in diameter, it is the seventh-largest moon in the Solar System, the only satellite of Neptune massive enough to be in hydrostatic equilibrium, the second-largest planetary moon in relation to its primary (after Earth's Moon), and larger than Pluto. Triton is one of the few moons in the Solar System known to be geologically active (the others being Jupiter's Io and Europa, and Saturn's Enceladus and Titan). As a consequence, its surface is relatively young, with few obvious impact craters. Intricate cryovolcanic and tectonic te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Webb Image Captures Clearest View Of Neptune’s Rings In Decades
New is an adjective referring to something recently made, discovered, or created. New or NEW may refer to: Music * New, singer of K-pop group The Boyz Albums and EPs * ''New'' (album), by Paul McCartney, 2013 * ''New'' (EP), by Regurgitator, 1995 Songs * "New" (Daya song), 2017 * "New" (Paul McCartney song), 2013 * "New" (No Doubt song), 1999 *"new", by Loona from '' Yves'', 2017 *"The New", by Interpol from '' Turn On the Bright Lights'', 2002 Acronyms * Net economic welfare, a proposed macroeconomic indicator * Net explosive weight, also known as net explosive quantity * Network of enlightened Women, a conservative university women's organization * Next Entertainment World, a South Korean film distribution company Identification codes * Nepal Bhasa language ISO 639 language code * New Century Financial Corporation (NYSE stock abbreviation) * Northeast Wrestling, a professional wrestling promotion in the northeastern United States Transport * New Orleans Lakefront Ai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shepherd Moon
A shepherd moon (also herder moon or watcher moon) is a small natural satellite that clears a gap in planetary-ring material or keeps particles within a ring contained. The name is a result of the fact they limit the "herd" of the ring particles as a shepherd. Due to their gravitational effect, they pick up particles and deflect them from their original orbits through orbital resonance. This causes gaps in the ring system, such as the particularly striking Cassini Division, as well as other characteristic bands, or strange "twisted" deformation of rings. Discovery The existence of shepherd moons was theorized in early 1979. Observations of the rings of Uranus show that they are very thin and well defined, with sharp gaps between rings. To explain this, Goldreich and Tremaine suggested that two small satellites that were undetected at the time might be confining each ring. The first images of shepherd satellites were taken later that year by Voyager 1. Examples Jupiter Sev ... [...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] |
Longitude Of The Periapsis
In celestial mechanics, the longitude of the periapsis, also called longitude of the pericenter, of an orbiting body is the longitude (measured from the point of the vernal equinox) at which the periapsis (closest approach to the central body) would occur if the body's orbit inclination were zero. It is usually denoted '' ϖ''. For the motion of a planet around the Sun, this position is called longitude of perihelion ϖ, which is the sum of the longitude of the ascending node Ω, and the argument of perihelion ω. The longitude of periapsis is a compound angle, with part of it being measured in the plane of reference and the rest being measured in the plane of the orbit. Likewise, any angle derived from the longitude of periapsis (e.g., mean longitude and true longitude) will also be compound. Sometimes, the term ''longitude of periapsis'' is used to refer to ''ω'', the angle between the ascending node and the periapsis. That usage of the term is especially common in discussions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Depth
In physics, optical depth or optical thickness is the natural logarithm of the ratio of incident to ''transmitted'' radiant power through a material. Thus, the larger the optical depth, the smaller the amount of transmitted radiant power through the material. Spectral optical depth or spectral optical thickness is the natural logarithm of the ratio of incident to transmitted spectral radiant power through a material. Optical depth is dimensionless, and in particular is not a length, though it is a monotonically increasing function of optical path length, and approaches zero as the path length approaches zero. The use of the term "optical density" for optical depth is discouraged. In chemistry, a closely related quantity called "absorbance" or "decadic absorbance" is used instead of optical depth: the common logarithm of the ratio of incident to transmitted radiant power through a material, that is the optical depth divided by ln 10. Mathematical definitions Optical depth O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rings Of Uranus
The rings of Uranus are intermediate in complexity between the more extensive set around Saturn and the simpler systems around Jupiter and Neptune. The rings of Uranus were discovered on March 10, 1977, by James L. Elliot, Edward W. Dunham, and Jessica Mink. William Herschel had also reported observing rings in 1789; modern astronomers are divided on whether he could have seen them, as they are very dark and faint.(re study by Stuart Eves) By 1977, nine distinct rings were identified. Two additional rings were discovered in 1986 in images taken by the ''Voyager 2'' spacecraft, and two outer rings were found in 2003–2005 in Hubble Space Telescope photos. In the order of increasing distance from the planet the 13 known rings are designated 1986U2R/ζ, 6, 5, 4, α, β, η, γ, δ, λ, ε, ν and μ. Their radii range from about 38,000 km for the 1986U2R/ζ ring to about 98,000 km for the μ ring. Additional faint dust bands and incomplete arcs may exist between the main ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiation
In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes: * ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma radiation (γ) * ''particle radiation'', such as alpha radiation (α), beta radiation (β), proton radiation and neutron radiation (particles of non-zero rest energy) * '' acoustic radiation'', such as ultrasound, sound, and seismic waves (dependent on a physical transmission medium) * ''gravitational wave, gravitational radiation'', that takes the form of gravitational waves, or ripples in the curvature of spacetime Radiation is often categorized as either ''ionizing radiation, ionizing'' or ''non-ionizing radiation, non-ionizing'' depending on the energy of the radiated particles. Ionizing radiation carries more than 10 electron volt, eV, which is enough to ionize atoms and molecules and break ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
