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120347 Salacia
120347 Salacia, provisional designation , is a large planetoid in the Kuiper belt, approximately 850 kilometers in diameter. As of 2018, it is located 44.8 astronomical units from the Sun, and reaches apparent magnitude 20.7 at opposition. Salacia was discovered on 22 September 2004, by American astronomers Henry Roe, Michael Brown and Kristina Barkume at the Palomar Observatory in California, United States. It has been observed 124 times, with precovery images back to 25 July 1982. Salacia orbits the Sun at an average distance that is slightly greater than that of Pluto. It was named after the Roman goddess Salacia and has a single known moon, Actaea. Brown estimated that Salacia is nearly certainly a dwarf planet. However, William Grundy ''et al.'' argue that objects in the size range of 400–1,000 km, with densities of ≈ 1.2 g/cm3 or less and albedos less than ≈ 0.2, have likely never compressed into fully solid bodies or been resurfaced, let alone diff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salacia Symbol (Moskowitz, Fixed Width)
In ancient Roman mythology, Salacia ( , ) was the female divinity of the sea, worshipped as the goddess of salt water who presided over the depths of the ocean. Neptune was her consort. That Salacia was the consort of Neptune is implied by Varro, and is positively affirmed by Seneca, Augustine and Servius. She is identified with the Greek goddess Amphitrite, consort of Poseidon. The god Neptune wanted to marry Salacia, but she was in great awe of her distinguished suitor, and to preserve her virginity, with grace and celerity she managed to glide out of his sight, and hid from him in the Atlantic Ocean. The grieving Neptune sent a dolphin to look for her and persuade the fair nymph to return and share his throne. Salacia agreed to marry Neptune and the King of the Deep was so overjoyed at these good tidings that the dolphin was awarded a place in the heavens, where he now forms a well known constellation Delphinus. Salacia is represented as a beautiful nymph, crowned with seaw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apparent Magnitude
Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's light caused by interstellar dust along the line of sight to the observer. The word ''magnitude'' in astronomy, unless stated otherwise, usually refers to a celestial object's apparent magnitude. The magnitude scale dates back to the ancient Roman astronomer Claudius Ptolemy, whose star catalog listed stars from 1st magnitude (brightest) to 6th magnitude (dimmest). The modern scale was mathematically defined in a way to closely match this historical system. The scale is reverse logarithmic: the brighter an object is, the lower its magnitude number. A difference of 1.0 in magnitude corresponds to a brightness ratio of \sqrt /math>, or about 2.512. For example, a star of magnitude 2.0 is 2.512 times as bright as a star of magnitude 3.0, 6. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trans-Neptunian Object
A trans-Neptunian object (TNO), also written transneptunian object, is any minor planet in the Solar System that orbits the Sun at a greater average distance than Neptune, which has a semi-major axis of 30.1 astronomical units (au). Typically, TNOs are further divided into the classical and resonant objects of the Kuiper belt, the scattered disc and detached objects with the sednoids being the most distant ones. As of October 2020, the catalog of minor planets contains 678 numbered and more than 2,000 unnumbered TNOs. The first trans-Neptunian object to be discovered was Pluto in 1930. It took until 1992 to discover a second trans-Neptunian object orbiting the Sun directly, 15760 Albion. The most massive TNO known is Eris, followed by Pluto, , , and . More than 80 satellites have been discovered in orbit of trans-Neptunian objects. TNOs vary in color and are either grey-blue (BB) or very red (RR). They are thought to be composed of mixtures of rock, amorphous carbon and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albedo
Albedo (; ) is the measure of the diffuse reflection of sunlight, solar radiation out of the total solar radiation and measured on a scale from 0, corresponding to a black body that absorbs all incident radiation, to 1, corresponding to a body that reflects all incident radiation. Surface albedo is defined as the ratio of Radiosity (radiometry), radiosity ''J''e to the irradiance ''E''e (flux per unit area) received by a surface. The proportion reflected is not only determined by properties of the surface itself, but also by the spectral and angular distribution of solar radiation reaching the Earth's surface. These factors vary with atmospheric composition, geographic location, and time (see position of the Sun). While bi-hemispherical reflectance is calculated for a single angle of incidence (i.e., for a given position of the Sun), albedo is the directional integration of reflectance over all solar angles in a given period. The temporal resolution may range from seconds (as ob ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haumea Family
The Haumea or Haumean family is the only identified trans-Neptunian collisional family; that is, the only group of trans-Neptunian objects (TNOs) with similar orbital parameters and spectra (nearly pure water-ice) that suggest they originated in the disruptive impact of a progenitor body. Calculations indicate that it is probably the only trans-Neptunian collisional family. Members are known as Haumeids. Members Characteristics The dwarf planet is the largest member of the family, and the core of the differentiated progenitor; other identified members are the moons of Haumea and the Kuiper belt objects , , , , , , , , and , all with an ejection velocity from Haumea of less than 150 m/s. The brightest Haumeids have absolute magnitudes (H) bright enough to suggest a size between 400 and 700 km in diameter, and so possible dwarf planets, if they had the albedos of typical TNOs; however, they are likely to be much smaller as it is thought they are water-icy bodies w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parameter Space
The parameter space is the space of possible parameter values that define a particular mathematical model, often a subset of finite-dimensional Euclidean space. Often the parameters are inputs of a function, in which case the technical term for the parameter space is domain of a function. The ranges of values of the parameters may form the axes of a plot, and particular outcomes of the model may be plotted against these axes to illustrate how different regions of the parameter space produce different types of behavior in the model. In statistics, parameter spaces are particularly useful for describing parametric families of probability distributions. They also form the background for parameter estimation. In the case of extremum estimators for parametric models, a certain objective function is maximized or minimized over the parameter space. Theorems of existence and consistency of such estimators require some assumptions about the topology of the parameter space. For instance, com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nice Model
The Nice () model is a scenario for the dynamical evolution of the Solar System. It is named for the location of the Côte d'Azur Observatory—where it was initially developed in 2005—in Nice, France. It proposes the migration of the giant planets from an initial compact configuration into their present positions, long after the dissipation of the initial protoplanetary disk. In this way, it differs from earlier models of the Solar System's formation. This planetary migration is used in dynamical simulations of the Solar System to explain historical events including the Late Heavy Bombardment of the inner Solar System, the formation of the Oort cloud, and the existence of populations of small Solar System bodies such as the Kuiper belt, the Neptune and Jupiter trojans, and the numerous resonant trans-Neptunian objects dominated by Neptune. Description The original core of the Nice model is a triplet of papers published in the general science journal ''Nature'' in 2005 by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deep Ecliptic Survey
The Deep Ecliptic Survey (DES) is a project to find Kuiper belt objects (KBOs), using the facilities of the National Optical Astronomy Observatory (NOAO). The principal investigator is Robert L. Millis. Since 1998 through the end of 2003, the survey covered 550 square degrees with Apparent magnitude, sensitivity of 22.5, which means an estimated 50% of objects of this magnitude have been found. The survey has also established the mean Kuiper Belt plane and introduced new cubewano#Toward a formal definition, formal definitions of the dynamical classes of Kuiper belt objects. The remarkable first observations and/or discoveries include: * 28978 Ixion, large plutino * 19521 Chaos (cubewano) * , the first Binary asteroid, binary trans-Neptunian object (TNO) * , the first object with perihelion too far to be affected (scattered) by Neptune and a large semi-major axis * , remarkable for its semi-major axis of more than 500 astronomical unit, AU and extreme orbital eccentricity, eccentr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scattered Disc
The scattered disc (or scattered disk) is a distant circumstellar disc in the Solar System that is sparsely populated by icy small solar system bodies, which are a subset of the broader family of trans-Neptunian objects. The scattered-disc objects (SDOs) have orbital eccentricities ranging as high as 0.8, inclinations as high as 40°, and perihelia greater than . These extreme orbits are thought to be the result of gravitational "scattering" by the gas giants, and the objects continue to be subject to perturbation by the planet Neptune. Although the closest scattered-disc objects approach the Sun at about 30–35 AU, their orbits can extend well beyond 100 AU. This makes scattered objects among the coldest and most distant objects in the Solar System. The innermost portion of the scattered disc overlaps with a torus-shaped region of orbiting objects traditionally called the Kuiper belt, but its outer limits reach much farther away from the Sun and farther above and be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salacia Orbit 2018
In ancient Roman mythology, Salacia ( , ) was the female divinity of the sea, worshipped as the goddess of salt water who presided over the depths of the ocean. Neptune was her consort. That Salacia was the consort of Neptune is implied by Varro, and is positively affirmed by Seneca, Augustine and Servius. She is identified with the Greek goddess Amphitrite, consort of Poseidon. The god Neptune wanted to marry Salacia, but she was in great awe of her distinguished suitor, and to preserve her virginity, with grace and celerity she managed to glide out of his sight, and hid from him in the Atlantic Ocean. The grieving Neptune sent a dolphin to look for her and persuade the fair nymph to return and share his throne. Salacia agreed to marry Neptune and the King of the Deep was so overjoyed at these good tidings that the dolphin was awarded a place in the heavens, where he now forms a well known constellation Delphinus. Salacia is represented as a beautiful nymph, crowned with seaw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dwarf Planet
A dwarf planet is a small planetary-mass object that is in direct orbit of the Sun, smaller than any of the eight classical planets but still a world in its own right. The prototypical dwarf planet is Pluto. The interest of dwarf planets to planetary geologists is that they may be geologically active bodies, an expectation that was borne out in 2015 by the ''Dawn'' mission to and the '' New Horizons'' mission to Pluto. Astronomers are in general agreement that at least the nine largest candidates are dwarf planets: Pluto, , , , , , , , and . Of these and the tenth-largest candidate , all but Sedna have either been visited by spacecraft (Pluto and Ceres) or have at least one known moon (Pluto, Eris, Haumea, Makemake, Gonggong, Quaoar, Orcus, and Salacia), which allows their masses and thus an estimate of their densities to be determined. Mass and density in turn can be fit into geophysical models in an attempt to determine the nature of these worlds. Some astronomers include ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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