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Capture Of Triton
Triton (moon), Triton, the largest Natural satellite, moon of the ice giant planet Neptune, is hypothesized to have been Gravitational capture, captured from heliocentric orbit. Triton is unusual as it is the only known large moon on a Retrograde and prograde motion, retrograde, highly-Orbital inclination, inclined orbit; that is, Triton orbits in the opposite direction Neptune rotates, and its orbit is not aligned with Neptune's equatorial plane. This conflicts with the conventional theory of moon formation, where large moons tend to form from circumplanetary disc, discs of debris and thus orbit prograde. As a result, astronomers have proposed various hypotheses on how Triton acquired its unusual orbital configuration, with capture hypotheses currently being the tentative consensus. The capture of Triton would have been a cataclysmic event, severely disrupting any pre-existing moons around Neptune while Triton itself experienced extreme tidal heating and possibly collisions with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nereid (moon)
Nereid, or Neptune II, is the third-largest moon of Neptune. It has the most eccentric orbit of all known moons in the Solar System. It was the second moon of Neptune to be discovered, by Gerard Kuiper in 1949. Discovery and naming Nereid was discovered on 1 May 1949 by Gerard P. Kuiper using photographic plates taken with the 82-inch telescope at the McDonald Observatory. He proposed the name in the report of his discovery. It is named after the Nereids, sea-nymphs of Greek mythology and attendants of the god Neptune. It was the second moon of Neptune to be discovered, and the last before the arrival of ''Voyager 2'' (not counting a single observation of an occultation by Larissa in 1981). Physical characteristics Nereid is third-largest of Neptune's satellites, and has a mean radius of about , similar to Saturn's moon Mimas. It is by far the largest normal irregular satellite known, having about two-thirds the mass of all irregular moons combined. ( Triton is much l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voyager 2 Neptune And Triton
Voyager may refer to: Computing and communications * LG Voyager, a mobile phone model manufactured by LG Electronics * NCR Voyager, a computer platform produced by NCR Corporation * Voyager (computer worm), a computer worm affecting Oracle databases * Voyager (library program), the integrated library system from Ex Libris Group * Voyager (web browser), a web browser for Amiga computers * Voyager Digital, a defunct cryptocurrency brokerage company * HP Voyager series, code name for a Hewlett-Packard series of handheld programmable calculators Transport Air * Airbus Voyager, Royal Air Force version of the Airbus A330 MRTT * Frequent flyer program of South African Airways * Egvoyager Voyager 203, an Italian ultralight aircraft * Raj Hamsa Voyager, an Indian ultralight trike design * Rutan Voyager, the first airplane to fly around the world nonstop without refuelling Land * Bombardier Voyager, a high-speed train operated in the United Kingdom ** Bombardier ''Voyager'' (Briti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rogue Planet
A rogue planet, also termed a free-floating planet (FFP) or an isolated planetary-mass object (iPMO), is an interstellar object of planetary mass which is not gravitationally bound to any star or brown dwarf. Rogue planets may originate from planetary systems in which they are formed and later ejected, or they can also form on their own, outside a planetary system. The Milky Way alone may have billions to trillions of rogue planets, a range the upcoming Nancy Grace Roman Space Telescope is expected to refine. Some planetary-mass objects may have formed in a similar way to stars, and the International Astronomical Union has proposed that such objects be called sub-brown dwarfs. A possible example is Cha 110913−773444, which may either have been ejected and become a rogue planet or formed on its own to become a sub-brown dwarf. Terminology The two first discovery papers use the names isolated planetary-mass objects (iPMO) and free-floating planets (FFP). Most astronomical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteus (Voyager 2)
In Greek mythology, Proteus ( ; ) is an early prophetic sea god or god of rivers and oceanic bodies of water, one of several deities whom Homer calls the "Old Man of the Sea" (''hálios gérôn''). Some who ascribe a specific domain to Proteus call him the god of "elusive sea change", which suggests the changeable nature of the sea or the liquid quality of water. He can foretell the future, but, in a mytheme familiar to several cultures, will change his shape to avoid doing so; he answers only to those who are capable of capturing him. From this feature of Proteus comes the adjective protean, meaning "versatile", "mutable", or "capable of assuming many forms". "Protean" has positive connotations of flexibility, versatility and adaptability. Name origin Proteus's name suggests the "first" (from Greek "" , "first"), as () is the "primordial" or the "firstborn". It is not certain to what this refers, but in myths where he is the son of Poseidon, it possibly refers to his being ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radioactive Decay
Radioactive decay (also known as nuclear decay, radioactivity, radioactive disintegration, or nuclear disintegration) is the process by which an unstable atomic nucleus loses energy by radiation. A material containing unstable nuclei is considered ''radioactive''. Three of the most common types of decay are Alpha decay, alpha, Beta decay, beta, and Gamma ray, gamma decay. The weak force is the Fundamental interactions, mechanism that is responsible for beta decay, while the other two are governed by the electromagnetic force, electromagnetic and nuclear forces. Radioactive decay is a randomness, random process at the level of single atoms. According to quantum mechanics, quantum theory, it is impossible to predict when a particular atom will decay, regardless of how long the atom has existed. However, for a significant number of identical atoms, the overall decay rate can be expressed as a decay constant or as a half-life. The half-lives of radioactive atoms have a huge range: f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convection
Convection is single or Multiphase flow, multiphase fluid flow that occurs Spontaneous process, spontaneously through the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoyancy). When the cause of the convection is unspecified, convection due to the effects of thermal expansion and buoyancy can be assumed. Convection may also take place in soft solids or mixtures where particles can flow. Convective flow may be Transient state, transient (such as when a Multiphasic liquid, multiphase mixture of oil and water separates) or steady state (see convection cell). The convection may be due to Gravity, gravitational, Electromagnetism, electromagnetic or Fictitious force, fictitious body forces. Convection (heat transfer), Heat transfer by natural convection plays a role in the structure of Earth's atmosphere, its oceans, and its Earth's mantle, mantle. Discrete convective cells in the atmosphere can be identified by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planetary Migration
Planetary migration occurs when a planet or other body in orbit around a star interacts with a disk of gas or planetesimals, resulting in the alteration of its orbital parameters, especially its semi-major axis. Planetary migration is the most likely explanation for hot Jupiters ( exoplanets with Jovian masses but orbits of only a few days). The generally accepted theory of planet formation from a protoplanetary disk predicts that such planets cannot form so close to their stars, as there is insufficient mass at such small radii and the temperature is too high to allow the formation of rocky or icy planetesimals. It has also become clear that terrestrial-mass planets may be subject to rapid inward migration if they form while the gas disk is still present. This may affect the formation of the cores of the giant planets (which have masses of the order of 10 to 1000 Earth masses), if those planets form via the core-accretion mechanism. Types of disk Gas disk Observ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kuiper Belt Object
The Kuiper belt ( ) is a circumstellar disc in the outer Solar System, extending from the orbit of Neptune at 30 astronomical units (AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but is far larger—20 times as wide and 20–200 times as massive. Like the asteroid belt, it consists mainly of small bodies or remnants from when the Solar System formed. While many asteroids are composed primarily of rock and metal, most Kuiper belt objects are composed largely of frozen volatiles (termed "ices"), such as methane, ammonia, and water. The Kuiper belt is home to most of the objects that astronomers generally accept as dwarf planets: Orcus, Pluto, Haumea, Quaoar, and Makemake. Some of the Solar System's moons, such as Neptune's Triton and Saturn's Phoebe, may have originated in the region. The Kuiper belt is named in honor of the Dutch astronomer Gerard Kuiper, who conjectured the existence of the belt in 1951. There were researchers befo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orbital Eccentricity
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: * Elliptic orbit: * Parabolic trajectory: * Hyperbolic trajectory: The eccentricity is given by e = \sqrt where ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charon (moon)
Charon ( or ), formal designation (134340) Pluto I, is the largest of the five known natural satellites of the dwarf planet Pluto. It has a mean radius of . Charon is the sixth-largest known trans-Neptunian object after Pluto, Eris, Haumea, Makemake, and Gonggong. It was discovered in 1978 at the United States Naval Observatory in Washington, D.C., using photographic plates taken at the United States Naval Observatory Flagstaff Station (NOFS). With half the diameter and one-eighth the mass of Pluto, Charon is a very large moon in comparison to its parent body. Its gravitational influence is such that the barycenter of the Plutonian system lies outside Pluto, and the two bodies are tidally locked to each other. The dwarf planet systems Pluto–Charon and Eris– Dysnomia are the only known examples of mutual tidal locking in the Solar System, though it is likely that – Vanth is another. The reddish-brown cap of the north pole of Charon is composed of tholins, o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geology Of Triton
The geology of Triton encompasses the physical characteristics of the surface, internal structure, and geological history of Neptune's largest moon Triton. With a mean density of , Triton is roughly 15-35% water ice by mass; Triton is a differentiated body, with an icy solid crust atop a probable subsurface ocean and a rocky core. As a result, Triton's surface geology is largely driven by the dynamics of water ice and other volatiles such as nitrogen and methane. Triton's geology is vigorous, and has been and continues to be influenced by its unusual history of capture, high internal heat, and its thin but significant atmosphere. Nearly nothing was known of Triton's geology until the ''Voyager 2'' spacecraft flew by the Neptune system in 1989, marking the first and only up-close observations of the moon as of 2024. A number of proposals have been made to follow up on ''Voyager 2''s discoveries, such as ''Trident'' and '' Triton Hopper''. Geological history Triton's retro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flyby (spaceflight)
A flyby () is a spaceflight operation in which a spacecraft passes in proximity to another body, usually a target of its space exploration mission and/or a source of a gravity assist (also called ''swing-by'') to impel it towards another target. Spacecraft which are specifically designed for this purpose are known as flyby spacecraft, although the term has also been used in regard to asteroid flybys of Earth for example. Important parameters are the time and distance of closest approach. Spacecraft flyby Flyby maneuvers can be conducted with a planet, a natural satellite or a non-planetary object such as a small Solar System body. Planetary flybys have occurred with Mars or Earth for example: * List of Earth flybys * Mars flyby An example of a comet flyby is when International Cometary Explorer (formerly ISEE-3) passed about from the nucleus of Comet Giacobini-Zinner in September 1985. Another application of the flyby is of Earth's Moon, usually called a lunar flyby. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
