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Satellite Planet
A planetary-mass moon is a planetary-mass object that is also a natural satellite. They are large and ellipsoidal (sometimes spherical) in shape. Two moons in the Solar System are larger than the planet Mercury (though less massive): Ganymede and Titan, and seven are larger and more massive than the dwarf planet . The concept of ''satellite planets'' – the idea that planetary-mass objects, including planetary-mass moons, are planets – is used by some planetary scientists, such as Alan Stern, who are more concerned with whether a celestial body has planetary geology (that is, whether it is a planetary body) than its solar or non-solar orbit ( planetary dynamics). This conceptualization of planets as three classes of objects (classical planets, dwarf planets and satellite planets) has not been accepted by the International Astronomical Union (the IAU). In addition, the IAU definition of 'hydrostatic equilibrium' is quite restrictive – that the object's mass be sufficient ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Large Moons (4089199369)
Large means of great size. Large may also refer to: Mathematics * Arbitrarily large, a phrase in mathematics * Large cardinal, a property of certain transfinite numbers * Large category, a category with a proper class of objects and morphisms (or both) * Large diffeomorphism, a diffeomorphism that cannot be continuously connected to the identity diffeomorphism in mathematics and physics * Large numbers, numbers significantly larger than those ordinarily used in everyday life * Large ordinal, a type of number in set theory * Large sieve, a method of analytic number theory ** Larger sieve, a heightening of the large sieve * Law of large numbers, a result in probability theory * Sufficiently large, a phrase in mathematics Other uses * ''Large'' (film), a 2001 comedy film * Large (surname), an English surname * LARGE, an enzyme * Large, a British English name for the maxima (music), a note length in mensural notation * Large, or G's, or grand, slang for $1,000 US dollars * Large, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Giovanni Cassini
Giovanni Domenico Cassini, also known as Jean-Dominique Cassini (8 June 1625 – 14 September 1712) was an Italian (naturalised French) mathematician, astronomer and engineer. Cassini was born in Perinaldo, near Imperia, at that time in the County of Nice, part of the Savoyard state. Cassini is known for his work on astronomy and engineering. He discovered four satellites of the planet Saturn (planet), Saturn and noted the division of the rings of Saturn; the Cassini Division was named after him. Giovanni Domenico Cassini was also the first of his family to begin work on the project of creating a topographic map of France. The Cassini–Huygens, ''Cassini'' space probe, launched in 1997, was named after him and became the fourth to visit the planet Saturn and the first to orbit the planet. Life Time in Italy Cassini was the son of Jacopo Cassini, a Tuscan, and Giulia Crovesi. In 1648 Cassini accepted a position at the observatory at Panzano, near Bologna, to work with Marqui ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Europa (moon)
Europa , or Jupiter II, is the smallest of the four Galilean moons orbiting Jupiter, and the sixth-closest to the planet of all the 80 known moons of Jupiter. It is also the sixth-largest moon in the Solar System. Europa was discovered in 1610 by Galileo Galilei and was named after Europa, the Phoenician mother of King Minos of Crete and lover of Zeus (the Greek equivalent of the Roman god Jupiter). Slightly smaller than Earth's Moon, Europa is primarily made of silicate rock and has a water-ice crust and probably an iron–nickel core. It has a very thin atmosphere, composed primarily of oxygen. Its white-beige surface is striated by light tan cracks and streaks, but craters are relatively few. In addition to Earth-bound telescope observations, Europa has been examined by a succession of space-probe flybys, the first occurring in the early 1970s. In September 2022, the ''Juno'' spacecraft flew within about 200 miles of Europa for a more recent close-up view. Europa ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Io (moon)
Io (), or Jupiter I, is the innermost and third-largest of the four Galilean moons of the planet Jupiter. Slightly larger than Earth’s moon, Io is the fourth-largest moon in the Solar System, has the highest density of any moon, the strongest surface gravity of any moon, and the lowest amount of water (by atomic ratio) of any known astronomical object in the Solar System. It was discovered in 1610 by Galileo Galilei and was named after the mythological character Io, a priestess of Hera who became one of Zeus's lovers. With over 400 active volcanoes, Io is the most geologically active object in the Solar System. This extreme geologic activity is the result of tidal heating from friction generated within Io's interior as it is pulled between Jupiter and the other Galilean moons—Europa, Ganymede and Callisto. Several volcanoes produce plumes of sulfur and sulfur dioxide that climb as high as above the surface. Io's surface is also dotted with more than 100 mountains that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moon
The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of Australia). The Moon is a planetary-mass object with a differentiated rocky body, making it a satellite planet under the geophysical definitions of the term and larger than all known dwarf planets of the Solar System. It lacks any significant atmosphere, hydrosphere, or magnetic field. Its surface gravity is about one-sixth of Earth's at , with Jupiter's moon Io being the only satellite in the Solar System known to have a higher surface gravity and density. The Moon orbits Earth at an average distance of , or about 30 times Earth's diameter. Its gravitational influence is the main driver of Earth's tides and very slowly lengthens Earth's day. The Moon's orbit around Earth has a sidereal period of 27.3 days. During each synodic period ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pluto
Pluto (minor-planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of trans-Neptunian object, bodies beyond the orbit of Neptune. It is the ninth-largest and tenth-most-massive known object to directly orbit the Sun. It is the largest known trans-Neptunian object by volume, by a small margin, but is slightly less massive than Eris (dwarf planet), Eris. Like other Kuiper belt objects, Pluto is made primarily of ice and rock and is much smaller than the inner planets. Compared to Moon, Earth's moon, Pluto has only one sixth its mass and one third its volume. Pluto has a moderately orbital eccentricity, eccentric and inclined orbit, ranging from from the Sun. Light from the Sun takes 5.5 hours to reach Pluto at its average distance (). Pluto's eccentric orbit periodically brings it closer to the Sun than Neptune, but a stable orbital resonance prevents them from colliding. Pluto has moons of Pluto, five known moons: Charon (moon), Charon, the larg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrostatic Equilibrium
In fluid mechanics, hydrostatic equilibrium (hydrostatic balance, hydrostasy) is the condition of a fluid or plastic solid at rest, which occurs when external forces, such as gravity, are balanced by a pressure-gradient force. In the planetary physics of Earth, the pressure-gradient force prevents gravity from collapsing the planetary atmosphere into a thin, dense shell, whereas gravity prevents the pressure-gradient force from diffusing the atmosphere into outer space. Hydrostatic equilibrium is the distinguishing criterion between dwarf planets and small solar system bodies, and features in astrophysics and planetary geology. Said qualification of equilibrium indicates that the shape of the object is symmetrically ellipsoid, where any irregular surface features are consequent to a relatively thin solid crust. In addition to the Sun, there are a dozen or so equilibrium objects confirmed to exist in the Solar System. Mathematical consideration For a hydrostatic fluid on Ear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Planemo
A planetary-mass object (PMO), planemo, or planetary body is by geophysical definition of celestial objects any celestial object massive enough to achieve hydrostatic equilibrium (to be rounded under its own gravity), but not enough to sustain core fusion like a star. The purpose of this term is to refer to a broader range of celestial objects than the concept of planet, since many objects similar in geophysical terms do not conform to typical expectations for a planet. Planetary-mass objects can be quite distinguished in origin and location. Planetary-mass objects include dwarf planets, planetary-mass satellite or free-floating planemos, which may have been ejected from a system (rogue planets) or formed through cloud-collapse rather than accretion (sometimes called sub-brown dwarfs). Types Planetary-mass satellite The three largest satellites Ganymede, Callisto, and Titan are of similar size or larger than the planet Mercury; these and four more – Io, Moon, Europa, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timeline Of Discovery Of Solar System Planets And Their Moons
The timeline of discovery of Solar System planets and their natural satellites charts the progress of the discovery of new bodies over history. Each object is listed in chronological order of its discovery (multiple dates occur when the moments of imaging, observation, and publication differ), identified through its various designations (including temporary and permanent schemes), and the discoverer(s) listed. Historically the naming of moons did not always match the times of their discovery. Traditionally, the discoverer enjoys the privilege of naming the new object; however, some neglected to do so ( E. E. Barnard stated he would "defer any suggestions as to a name" or Amalthea"until a later paper" but never got around to picking one from the numerous suggestions he received) or actively declined ( S. B. Nicholson stated "Many have asked what the new satellites ysithea and Carmeare to be named. They will be known only by the numbers X and XI, written in Roman numerals, and usu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oberon (moon)
Oberon , also designated , is the outermost major moon of the planet Uranus. It is the second-largest and second most massive of the Uranian moons, and the ninth most massive moon in the Solar System. Discovered by William Herschel in 1787, Oberon is named after the mythical king of the fairies who appears as a character in Shakespeare's ''A Midsummer Night's Dream''. Its orbit lies partially outside Uranus's magnetosphere. It is likely that Oberon formed from the accretion disk that surrounded Uranus just after the planet's formation. The moon consists of approximately equal amounts of ice and rock, and is probably differentiated into a rocky core and an icy mantle. A layer of liquid water may be present at the boundary between the mantle and the core. The surface of Oberon, which is dark and slightly red in color, appears to have been primarily shaped by asteroid and comet impacts. It is covered by numerous impact craters reaching 210 km in diameter. Oberon possesses a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titania (moon)
Titania (), also designated Uranus III, is the largest of the moons of Uranus and the List of natural satellites by diameter, eighth largest moon in the Solar System at a diameter of . Discovered by William Herschel in 1787, it is named after the Titania (A Midsummer Night's Dream), queen of the fairies in Shakespeare's ''A Midsummer Night's Dream''. Its orbit lies inside Uranus's magnetosphere. Titania consists of approximately equal amounts of ice and rock (geology), rock, and is probably differentiated into a rocky core (geology), core and an icy mantle (geology), mantle. A layer of liquid water may be present at the core–mantle boundary. Its surface, which is relatively dark and slightly red in color, appears to have been shaped by both impacts and endogenic processes. It is covered with numerous impact craters reaching up to in diameter, but is less heavily cratered than Oberon (moon), Oberon, outermost of the five large moons of Uranus. It may have undergone an early end ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dione (moon)
Dione () is a moon of Saturn. It was discovered by Italian astronomer Giovanni Domenico Cassini in 1684. It is named after the Titaness Dione of Greek mythology. It is also designated Saturn IV. Name Giovanni Domenico Cassini named the four moons he discovered ( Tethys, Dione, Rhea and Iapetus) ''Sidera Lodoicea'' ("the stars of Louis") to honor king Louis XIV. Cassini found Dione in 1684 using a large aerial telescope he set up on the grounds of the Paris Observatory. The satellites of Saturn were not named until 1847, when William Herschel's son John Herschel published ''Results of Astronomical Observations made at the Cape of Good Hope,'' suggesting that the names of the Titans (sisters and brothers of Cronus) be used. Orbit Dione orbits Saturn with a semimajor axis about 2% less than that of the Moon. However, reflecting Saturn's greater mass (95 times that of Earth), Dione's orbital period is one tenth that of the Moon. Dione is currently in a 1:2 mean-motion or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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