To be gravitationally captured by a planet, a passing body must lose sufficient energy to be slowed down to a speed less than that required to escape. [27], Europa, along with Jupiter's three other large moons, Io, Ganymede, and Callisto, was discovered by Galileo Galilei on 8 January 1610,[1] and possibly independently by Simon Marius. [26] Data sent back by the two spacecraft was used to determine the moon's physical characteristics[105] and provided images of the surface with up to 400km (250mi) resolution. The accumulated carbon dioxide ice can be removed from cold traps by magnetospheric particles, which sputter it from the surface. Little was known about the satellite until Voyager 2 flew by in 1989. Pioneer 11 made a similar flyby in 1974. It has a diameter of 910 km (570 mi). Despite the presence of a gas torus, Europa has no weather producing clouds. Very low curvilinear ridge with a scalloped pattern. Such plume activity could help researchers in a search for life from the subsurface Europan ocean without having to land on the moon. [23][24], Titania is the largest and most massive Uranian moon, and the eighth most massive moon in the Solar System. [81] In either case, because these materials are colorless or white when pure, some other material must also be present to account for the reddish color, and sulfur compounds are suspected. [20] This method was also applied by the same authors to measure the size of the dwarf planet Eris. [29] They obliterated the original heavily cratered terrain, explaining the relatively low number of impact craters on the moon's present-day surface. [136][137] The aims of these missions have ranged from examining Europa's chemical composition to searching for extraterrestrial life in its hypothesized subsurface oceans. All but three features on Venus are named after female personages (goddesses and historical or mythological women). [103] Today, Ganymede continues to cool slowly. Shakespeare's character's name is pronounced /ttenj/, but the moon is often pronounced /tateni/, by analogy with the familiar chemical element titanium. [27] If this is the case, the radius of the core 520 kilometres (320mi) is about 66% of the radius of the moon, and its mass is around 58% of the moon's massthe proportions are dictated by moon's composition. It might be produced locally from carbonates or organic materials under the influence of the solar ultraviolet radiation or energetic charged particles coming from the magnetosphere of Uranus. The thickness of this ocean, if it exists, is up to 50 kilometres (31mi) and its temperature is around 190K (close to the waterammonia eutectic temperature of 176K). WebPath or Path Frres (French pronunciation: [pate f], styled as PATH!) [18] In 1851 Lassell eventually numbered all four known satellites in order of their distance from the planet by Roman numerals, and since then Titania has been designated Uranus III.[19]. [32] However, the name's spelling was later reconsidered by Brown due to its ambiguous pronunciation resulting from the four-vowel combination uaoano other word in the English language has this particular combination of vowels. Landslide debris. [citation needed] One example is flexure analysis, in which Europa's crust is modeled as a plane or sphere weighted and flexed by a heavy load. Combined, they are nearly the size of Kraken Mare on Titan. [173] Life on Europa could exist clustered around hydrothermal vents on the ocean floor, or below the ocean floor, where endoliths are known to inhabit on Earth. Even so, the names Marius assigned are used today: Ganymede, Callisto, Io, and Europa. Gods, goddesses, and other beings associated with the Underworld from mythology, folklore and literature. [7] An early theory of how Triton may have been slowed was by collision with another object, either one that happened to be passing by Neptune (which is unlikely), or a moon or proto-moon in orbit around Neptune (which is more likely). Material from Europas ocean that ends up on the surface will be bombarded by radiation, possibly destroying any biosignatures, or chemical signs that could imply the presence of life. The other four regular satellites are much smaller and closer to Jupiter; these serve as sources of the dust that makes up Jupiter's rings. Because Triton's Bond albedo is among the highest in the Solar System, it is sensitive to small variations in spectral albedo. Pronounce Europa in English (Australia) [91] In these areas, the energetic (tens and hundreds of kiloelectronvolt) electrons and ions have been detected,[83] which may cause the auroras observed around the Ganymedian poles. [48] A number of other moons have only been observed for a year or two, but have decent enough orbits to be easily measurable at present.[47]. [4][5] Tidal interactions also cause Triton's orbit, which is already closer to Neptune than the Moon is to Earth, to gradually decay further; predictions are that 3.6billion years from now, Triton will pass within Neptune's Roche limit. [8], The radiation level at the surface of Ganymede is considerably lower than at Europa, being 5080 mSv (58 rem) per day, an amount that would cause severe illness or death in human beings exposed for two months. [33] The former acted over the moon's entire history and influenced all surfaces. Ganymede's larger mass means that it would have migrated inward at a faster rate than Europa or Io. [33] The practice was to name newly discovered moons of Jupiter after lovers and favorites of the god Jupiter (Zeus) and, since 2004, also after their descendants. Listen to the audio pronunciation in English. [22][37] High spatial resolution spectra of Ganymede taken by Galileo were used to identify several non-ice compounds on the surface. At just over 3,100 kilometres (1,900mi) in diameter, it is the sixth-largest moon and fifteenth-largest object in the Solar System. [120] This accumulated oxygen atmosphere can get to a height of 125 miles above the surface of Europa. [21] Since then (2006), crystalline water ice was also found on Haumea, but present in larger quantities and thought to be responsible for the very high albedo of that object (0.7). In the polar cap regions, at latitudes higher than 30, magnetic field lines are open, connecting Ganymede with Jupiter's ionosphere. Europas torus ionizes through the process of neutral particles exchanging electrons with its charged particles. [4][5], Triton's eccentric post-capture orbit would have also resulted in tidal heating of its interior, which could have kept Triton fluid for a billion years; this inference is supported by evidence of differentiation in Triton's interior. Names for atmospheric features are informal at present; a formal system will be chosen in the future. The name Titania is ancient Greek for "Daughter of the Titans". [21], Because Uranus orbits the Sun almost on its side, and its moons orbit in the planet's equatorial plane, they (including Titania) are subject to an extreme seasonal cycle. Although it has few craters, it is thought that this is the oldest terrain on Triton. [99][100][101][102] In the latter case, modeling suggests that differentiation would become a runaway process at Ganymede but not Callisto. [21][22][23][24], The Galileo mission, launched in 1989, provides the bulk of current data on Europa. [10], With the aid of telescopic photography, further discoveries followed quickly over the course of the 20th century. Planetary nomenclature, like terrestrial nomenclature, is a system of uniquely identifying features on the surface of a planet or natural satellite so that the features can be easily located, described, and discussed. The dipole magnetic field created by this permanent moment has a strength of 719 2 nT at Ganymede's equator,[22] which should be compared with the Jovian magnetic field at the distance of Ganymedeabout 120 nT. The astronomical literature instead simply referred to "Jupiter I", "Jupiter II", etc., or "the first satellite of Jupiter", "Jupiter's second satellite", and so on. Once approved by the WGPSN, names are considered official and can be used on maps and in publications. In general, the naming convention for a feature type remains the same regardless of its size. In addition to these general rules, each task group develops additional conventions as it formulates an interesting and meaningful nomenclature for individual planetary bodies. The first picture NASAs Juno spacecraft took as it flew by Jupiters ice-encrusted moon Europa has arrived on Earth. The masses of the inner satellites are estimated by assuming a density similar to Amalthea's (. [103] The convective motions in Callisto have caused only a partial separation of rock and ice. "An Account of the Discovery of Two Satellites Revolving Round the Georgian Planet", Brave New Worlds: The Shakespearean Moons of Uranus, "Planetary Satellite Mean Orbital Parameters", "Titania's radius and an upper limit on its atmosphere from the September 8, 2001 stellar occultation", "Voyager 2 in the Uranian System: Imaging Science Results", "On the Georgian Planet and Its Satellites", "On the Discovery of Four Additional Satellites of the Georgium Sidus. Mietwagen. Diameters with multiple entries such as "604034" reflect that the body is not a perfect, The only satellites with measured masses are Amalthea, Himalia, and the four Galilean moons. Browse the use examples 'Europa' in the great English corpus. The first reported observation of Io and Europa was made by Galileo on 7 January 1610 using a 20-magnification refracting telescope at the University of Padua. Titania consists of approximately equal amounts of ice and rock, and is probably differentiated into a rocky core and an icy mantle. [32] In much of the earlier astronomical literature, Europa is simply referred to by its Roman numeral designation as Jupiter II (a system also introduced by Galileo) or as the "second satellite of Jupiter". Originally called S/2003 J13, Cyllene was named for a nymph in Greek mythology who was a daughter of Zeus, the Greek equivalent of the Roman god Jupiter. The Galilean satellites are nearly spherical in shape due to their planetary mass, and so would be considered at least dwarf planets if they were in direct orbit around the Sun. Full confirmation of the lakes' existence will require a space mission designed to probe the ice shell either physically or indirectly, for example, using radar. [46] The surface is moderately red, meaning that Quaoar is relatively more reflective in the red and near-infrared spectrum than in the blue. People and places associated with the Amalthea myth. Water ice comprises 1535% and frozen carbon dioxide (dry ice) the remaining 1020%. [109], The Pioneer and Voyager flybys were all at large distances and high speeds, as they flew on unbound trajectories through the Jupiter system. [33], The geology of Titania was influenced by two competing forces: impact crater formation and endogenic resurfacing. [32][a] (Indeed, even if one takes the u to be part of the initial consonant qu, it then only appears at Kaoani but it also appears in proper nouns such as Laoag and Paraoa) Regardless, the name and discovery of Quaoar were publicly announced in October, though Brown had not sought approval of the name by the IAU's Committee on Small Body Nomenclature (CSBN). These various fractures are thought to have been caused in large part by the tidal flexing exerted by Jupiter. [62], Other features present on Europa are circular and elliptical lenticulae (Latin for "freckles"). [32][43] Because Quaoar's orbital inclination is greater than 4 degrees, it is part of the dynamically hot population of high-inclination classical Kuiper belt objects. Ships of discovery or scientific expeditions, Abandoned cities, towns or settlements of antiquity, Over 20km, famous women; under 20km, common female first names, Goddesses, miscellaneous (also one radar scientist), Giantesses and Titanesses (also two Greek alphanumeric), Word for planet Venus in various world languages (400km and longer); river goddesses (less than 400km in length), Craters are generally named after deceased scientists, scholars, artists and explorers who have made outstanding or fundamental contributions to their field. [1] By the time the present (possibly fifth) generation formed, the disk had thinned so that it no longer greatly interfered with the moons' orbits. [10][46] A haze permeates most of Triton's troposphere, thought to be composed largely of hydrocarbons and nitriles created by the action of sunlight on methane. Named after the Titan Iapetus, the moon was discovered in 1671 by Giovanni Domenico Cassini.. A relatively low-density body made up mostly of ice, Glosbe uses cookies to ensure you get the best experience a main belt asteroid; not to be confused with the Jovian moon. [8][15] The upper limit of atmosphere pressure was tightened to 10 nanobars after another stellar occultation in 2019. The larger bands are more than 20km (12mi) across, often with dark, diffuse outer edges, regular striations, and a central band of lighter material. The puzzling, fascinating surface of Jupiters icy moon Europa looms large in this newly-reprocessed color view, made from images taken by NASA's Galileo spacecraft in the late 1990s. The NASA and JAXA components were later cancelled, and ESA's appeared likely to be cancelled too,[123] but in 2012 ESA announced it would go ahead alone. [4][33], Europa orbits Jupiter in just over three and a half days, with an orbital radius of about 670,900km. The name Titania was taken from the Queen of the Fairies in A Midsummer Night's Dream. The largest impact structures are surrounded by concentric rings and appear to be filled with relatively flat, fresh ice; based on this and on the calculated amount of heat generated by Europan tides, it is estimated that the outer crust of solid ice is approximately 1030km (619mi) thick,[73] including a ductile "warm ice" layer, which could mean that the liquid ocean underneath may be about 100km (60mi) deep. [40] The symbol was designed by Denis Moskowitz, a software engineer in Massachusetts; it combines the letter Q (for 'Quaoar') with a canoe, and is stylized to recall angular Tongva rock art. Accessible and authoritative sources, including Internet sources, are required for adopted names. [69][70] Although larger craters have been observed, they are generally thought to be volcanic in nature. [107], Voyager 1 and Voyager 2 both studied Ganymede when passing through the Jupiter system in 1979. Mensae, Montes, Plana, Regiones and Tholi, These features can be named after places associated with. [22], Quaoar's rotation period is uncertain, and two possible rotation periods of Quaoar are given (8.64 hours or 17.68 hours). By January 1610, he had sighted the four massive Galilean [137][158] It was part of Project Prometheus. These families bear the names of their largest members. [129] This torus was officially confirmed using Energetic Neutral Atom (ENA) imaging. [54], At the time of its discovery in 2002, Quaoar was the largest object found in the Solar System since the discovery of Pluto. [1][3] Since Quaoar is not in a mean-motion resonance with Neptune, it is also classified as a classical Kuiper belt object (cubewano) by the Minor Planet Center and Deep Ecliptic Survey. [28][29] There may be an asymmetry between the leading and trailing hemispheres;[30] the former appears to be redder than the latter by 8%. [75][76] Another concept, involving a flyby, was formally proposed in 2019 as part of NASA's Discovery Program under the name Trident. When there is too much stress, it cracks. (continent) a. Europe. However, it has not yet been determined when this hypothesized shift in the spin axis might have occurred. Island (islands), an isolated land area (or group of such areas) surrounded by, or nearly surrounded by, a liquid area (sea or lake). They are also listed in the Gazetteer of Planetary Nomenclature. The magnetic dipole is tilted with respect to the rotational axis of Ganymede by 176, which means that it is directed against the Jovian magnetic moment. [130], The atmosphere of Europa was first discovered in 1995 by Hall Al. The rocks settled to the center, forming the core. [65][66], In November 2011, a team of researchers from the University of Texas at Austin and elsewhere presented evidence in the journal Nature suggesting that many "chaos terrain" features on Europa sit atop vast lakes of liquid water. [32] This provided him additional time for follow-up observations and took advantage of the whole observing session in July to analyze Quaoar's spectrum and characterize its surface composition.[22][32]. [35] Some of the most recently confirmed moons have not received names. The Galileo spacecraft was the first to enter orbit around Jupiter, arriving in 1995 and studying it until 2003. Because of its retrograde orbit and composition similar to Pluto, Triton is [90] The equatorial field of Ganymede is directed against the Jovian field, meaning reconnection is possible. All of them identified Triton as being a prime target and a separate Triton lander comparable to the Huygens probe for Titan was frequently included in those plans. Used only on Venus. Larger Kuiper belt objects are often much brighter because they are covered in more fresh ice and have a higher albedo, and thus they present a neutral color. The initial accretional heating together with continued decay of radioactive elements were probably strong enough to melt the ice if some antifreeze like ammonia (in the form of ammonia hydrate) or salt was present. [101][102], After formation, Ganymede's core largely retained the heat accumulated during accretion and differentiation, only slowly releasing it to the ice mantle. [8] Some research has suggested that, given its relatively small size, the core ought to have sufficiently cooled to the point where fluid motions, hence a magnetic field would not be sustained. [20] These are tiny moons, in long, eccentric, generally retrograde orbits, and averaging 3km (1.9mi) in diameter, with the largest being just 9km (5.6mi) across. Satellite rings and gaps in the rings are named for scientists who have studied these features; drawings that show these names are also included in the pertinent Transactions volume. The boundaries of many large features (such as terrae, regiones, planitiae and plana) are not topographically or geomorphically distinct; the coordinates of these features are identified from an arbitrarily chosen center point. This indicates that solar heating, although very weak at Triton's great distance from the Sun, plays a crucial role. [44], Quaoar's albedo or reflectivity could be as low as 0.1, similar to Varuna's albedo of 0.127. This term is implicit. If correct, this would explain many of Europa's features. spring vi (originate) nascere, derivare vi (informale) saltare fuori, spuntare vi : The whole project sprang from a conversation I had with a neighbour. Europa was discovered in 1610 by Galileo Galilei[1] 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). However, only 2% of the proto-disk mass of Jupiter is required to explain the existing satellites. WebChinese historian Xi Zezong claimed that the earliest record of a Jovian moon (Ganymede or Callisto) was a note by Chinese astronomer Gan De of an observation around 364 BC regarding a "reddish star". (29 February 2000), "Planet and Satellite Names and Discoverers", "JPL HORIZONS solar system data and ephemeris computation service", "Planetary Satellite Physical Parameters", "Free and forced obliquities of the Galilean satellites of Jupiter", "Suddenly, It Seems, Water Is Everywhere in Solar System", "New Europa Pictures Beamed Home by NASA's Juno Spacecraft - The space probe has been studying Jupiter since 2016 and just flew within about 200 miles of the surface of the ice-covered ocean moon", "Scientists Find Evidence of 'Diving' Tectonic Plates on Europa", "NASA Research Reveals Europa's Mystery Dark Material Could Be Sea Salt", "Hubble Sees Evidence of Water Vapor at Jupiter Moon", "Old Data Reveal New Evidence of Europa Plumes", "NASA Finds Signs of Plumes From Europa, Jupiter's Ocean Moon", "This May Be the Best Evidence Yet of a Water Plume on Jupiter's Moon Europa", "Esa selects 1bn-euro Juice probe to Jupiter", "NASA plots daring flight to Jupiter's watery moon", "Simon Marius (January 20, 1573 December 26, 1624)", "Europa, a Continuing Story of Discovery", Long-stressed Europa Likely Off-kilter at One Time, "Europa's Crust and Ocean: Origin, Composition, and the Prospects for Life", Europa may have towering ice spikes on its surface, "Formation of metre-scale bladed roughness on Europa's surface by ablation of ice", "Chapter 18: Ages and Interiors: the Cratering Record of the Galilean Satellites", "SPS 1020 (Introduction to Space Sciences)", "Europa: Facts about Jupiter's Moon, Europa The Planets", "Europa: Tidal heating of upwelling thermal plumes and the origin of lenticulae and chaos melting", "Scientists Find Evidence for "Great Lake" on Europa and Potential New Habitat for Life", "Impact breaching of Europa's ice: Constraints from numerical modeling: IMPACT BREACHING OF EUROPA'S ICE", "Impact penetration of Europa's ice crust as a mechanism for formation of chaos terrain", "Water near surface of a Jupiter moon only temporary", "Europa Mission to Probe Magnetic Field and Chemistry", "Atmospheric Prebiotic Chemistry and Organic Hazes", "Sodium chloride on the surface of Europa", "Frequently Asked Questions about Europa", "Scientist Explains Why Jupiter's Moon Europa Could Have Energetic Liquid Oceans", "Jupiter's Moon Europa Does The Wave To Generate Heat", "Europa's heaving ice might make more heat than scientists thought", "Photo composite of suspected water plumes on Europa", "Hubble discovers water vapour venting from Jupiter's moon Europa", "Jupiter Moon Europa May Have Water Geysers Taller Than Everest", "Cryomagmatic Mechanisms for the Formation of Rhadamanthys Linea,Triple Band Margins, and Other Low-Albedo Features on Europa", "Constraints on the Detection of Cryovolcanic Plumes on Europa", "CA measurement of water vapour amid a largely quiescent environment on Europa", "Signs of Europa Plumes Remain Elusive in Search of Cassini Data", "Hubble finds additional evidence of water vapor plumes on Europa", Annual Review of Earth and Planetary Sciences, "NASA: Activity Spied on Europa, But It's 'NOT Aliens', "Considerations for effusive cryovolcanism on Europa:The post-Galileo perspective", "Potential Plumes on Europa Could Come From Water in the Crust", "Life Beyond Earth - The Habitable Zone - Europa", "Hubble Finds Oxygen Atmosphere on Jupiter's Moon, Europa", "Hubble Finds Oxygen Atmosphere On Jupiter's Moon Europa", "Do Uranus's Moons Have Subsurface Oceans? When space probes have landed on Mars, individual small features such as rocks, dunes, and hollows have often been given informal names. Exploration of Europa began with the Jupiter flybys of Pioneer 10 and 11 in 1973 and 1974 respectively. [59] Studies of Voyager and Galileo images have revealed evidence of subduction on Europa's surface, suggesting that, just as the cracks are analogous to ocean ridges,[60][61] so plates of icy crust analogous to tectonic plates on Earth are recycled into the molten interior. [40], It is estimated that Europa has an outer layer of water around 100km (62mi) thick--a part frozen as its crust and a part as a liquid ocean underneath the ice. This page is an archive of past discussions. Eventually, after reducing chaos to order, they created the great seven giants that upheld the world. [52], The ionizing radiation level at the surface of Europa is equivalent to a dose of about 5.4Sv (540rem) per day,[53] an amount that would cause severe illness or death in human beings exposed for a single Earth-day (24 hours). Schaber (1982) "Geology of Europa", in David Morrison, ed., Schenk, Paul M.; Chapman, Clark R.; Zahnle, Kevin; and Moore, Jeffrey M. (2004), Ringwald, Frederick A. Triton's rotation is tidally locked to be synchronous with its orbit around Neptune: it keeps one face oriented toward the planet at all times. Rups are named after nearby mountain ranges (see above). Both northern and southern poles spend 42 years in a complete darkness, and another 42 years in continuous sunlight, with the sun rising close to the zenith over one of the poles at each solstice. [36] After the end of formation, the subsurface layer cooled, while the interior of Titania heated due to decay of radioactive elements present in its rocks. [12] Derived from the rotational light curves of Quaoar observed on March through June 2003, its rotation period is measured to be 17.6788 hours. [96] This relatively fast formation prevented the escape of accretional heat, which may have led to ice melt and differentiation: the separation of the rocks and ice. [21] A small amount of methane is present on its surface, which can only be retained by the largest Kuiper belt objects. [29] The images cover about 40% of the surface, but only 24% was photographed with the precision required for geological mapping. As a result of the moons particle venting, the atmosphere requires continuous replenishment. [22] Two more were discovered in 2017 by the team led by Scott S. Sheppard at the Carnegie Institution for Science, bringing the total to 69. WebProviene da una delle pi antiche famiglie d'Europa. Koulouris,(Esq. [8][9] The estimates come from observations of stellar occultations by Quaoar, in which it passes in front of a star, in 2013 and 2019. When more than one spelling of a name is extant, the spelling preferred by the person, or used in an authoritative reference, should be used. The most massive of the moons are the four Galilean moons: Io, Europa, Ganymede, and Callisto, which were independently discovered in 1610 by Galileo Galilei and Simon Marius and were the first objects found to orbit a body that was neither Earth nor the Sun. The other moons were simply labeled by their Roman numeral (e.g. The empty string is the special case where the sequence has length zero, so there are no symbols in the string. Such additional heat would have allowed the ocean to remain liquid for a longer time. Galileo flew by Europa in 1997 within 206km (128mi) of the moon's surface and the researchers suggest it may have flown through a water plume. [32] They consulted tribal historian Marc Acua, who suggested that the name Kwawar was appropriate for the newly discovered object. [174] In 2010, a model proposed by Richard Greenberg of the University of Arizona proposed that irradiation of ice on Europa's surface could saturate its crust with oxygen and peroxide, which could then be transported by tectonic processes into the interior ocean. Image Credits: A. Mura -Juno/JIRAM - ASI/INAF/JPL-Caltech/SwRI [114], Largest moon of Jupiter and in the Solar System, Periapsis is derived from the semimajor axis (, Apoapsis is derived from the semimajor axis (, It is probable that the German astronomer. [36] The maximum temperature of around 250K (23C) was reached at a depth of about 60 kilometres (37mi). The freezing of the water would have caused the interior to expand, which may have been responsible for the formation of the majority of the canyons. Bentigen Sie einen Mietwagen? Planets & Moons Pronunciation Guide. The first closeup photos were of low resolution compared to later missions. These may include landing sites, spacecraft impact sites, and small topographic features, such as craters, hills, and rocks. [138][139] Robotic missions to Europa need to endure the high-radiation environment around Jupiter. [178] Some scientists have speculated that life on Earth could have been blasted into space by asteroid collisions and arrived on the moons of Jupiter in a process called lithopanspermia.[179]. It was found to have a retrograde orbit, at a very high angle of inclination to the plane of Neptune's orbit. By comparison, the Moon reflects only 11%. The reason for this is that the direction of the spin pole may change by as much as a few degrees per day, completing one precession period over several months. The study's model, using images from the Galileo space probe, proposed that a combination of freezing and pressurization may result in at least some of the cryovolcanic activity. [51] The 40% of Triton's surface imaged by Voyager 2 revealed blocky outcrops, ridges, troughs, furrows, hollows, plateaus, icy plains and few craters. [97] This hypothesis explains why the two Jovian moons look so dissimilar, despite their similar mass and composition. There is enough rock in Triton's interior for radioactive decay to maintain a liquid subsurface ocean to this day, similar to what is thought to exist beneath the surface of Europa and a number of other icy outer Solar System worlds. Find stories, updates and expert opinion. A field of dunes. Streaks on Triton's surface left by geyser plumes suggest that the troposphere is driven by seasonal winds capable of moving material of over a micrometer in size. As for the larger objects, official names for any such small features would have to conform to established IAU rules and categories. These moons were probably captured by Jupiter from solar orbits. From the point of view of spoken language, its closest relatives are Ukrainian, Belarusian, and Rusyn, the [27][34] Quaoar was the 1,512th object discovered in the first half of June, as indicated by the preceding letter and numbers in its provisional designation. As Europa comes slightly nearer to Jupiter, Jupiter's gravitational attraction increases, causing Europa to elongate towards and away from it. It has been theorized that these ions are responsible for the plasma within Jupiter's magnetosphere. Most geologists who have studied Europa favor what is commonly called the "thick ice" model, in which the ocean has rarely, if ever, directly interacted with the present surface. [72] Data from the approach of Voyager 2 to Neptune on August 25, 1989, led to a more accurate estimate of Triton's diameter (2,706km). Check out the pronunciation, synonyms and grammar. [31] The regions along some scarps and near Ursula appear smooth at Voyager's image resolution. [21], Except for water, the only other compound identified on the surface of Titania by infrared spectroscopy is carbon dioxide, which is concentrated mainly on the trailing hemisphere. [115] A press release from NASA's Jet Propulsion Laboratory referencing the November 2020 study suggested that plumes sourced from migrating liquid pockets could potentially be less hospitable to life. The surface of Orcus is relatively bright with albedo reaching 23 percent, neutral in color and rich in water ice. The temperature on Europa varies from 160 C at the equatorial line, to 220 C at either of its poles. [64], An alternative hypothesis suggests that lenticulae are actually small areas of chaos and that the claimed pits, spots and domes are artefacts resulting from over-interpretation of early, low-resolution Galileo images. Ring and ring-gap nomenclature and names for newly discovered satellites are developed in joint deliberation between WGPSN and IAU Commission 20. For the spaceship in the 1960s television series Lost in Space, see, Europa in true colour, with its surface predominantly white. A census of Triton's craters imaged by Voyager 2 found only 179 that were incontestably of impact origin, compared with 835 observed for Uranus's moon Miranda, which has only three percent of Triton's surface area. [note 1] Their orbital shapes range from nearly perfectly circular to highly eccentric and inclined, and many revolve in the direction opposite to Jupiter's rotation (retrograde motion). [25][31] Quaoar's discovery has been cited by Brown as having contributed to the reclassification of Pluto as a dwarf planet. [1] Signs of water ice on the surface of Quaoar have been found, which suggests that cryovolcanism may be occurring on Quaoar. In September 2022, the Juno spacecraft flew within about 200 miles of Europa for a more recent close-up view. By the time that the Voyager space probes reached Jupiter, around 1979, 13 moons had been discovered, not including Themisto, which had been observed in 1975,[18] but was lost until 2000 due to insufficient initial observation data. [17][36] The ultimate source of this energy is Jupiter's rotation, which is tapped by Io through the tides it raises on Jupiter and is transferred to Europa and Ganymede by the orbital resonance. This is the opposite of what is observed on Oberon, where the trailing hemisphere exhibits stronger water ice signatures. Trujillo's website on Quaoar gives a three-syllable pronunciation, Polar dimension calculated by multiplying the measured equatorial diameter, In the convention for minor planet provisional designations, the first letter represents the half-month of the year of discovery while the second letter and numbers indicate the order of discovery within that half-month. Near the lower right limb are several dark maculae ("strange spots"). Montes are named after terrestrial mountain ranges or nearby craters. WebPassword requirements: 6 to 30 characters long; ASCII characters only (characters found on a standard US keyboard); must contain at least 4 different symbols; Impurities in the water ice crust of Europa are presumed both to emerge from the interior as cryovolcanic events that resurface the body, and to accumulate from space as interplanetary dust. [19], No additional moons were discovered for two decades, but between October 1999 and February 2003, researchers found another 34 moons using sensitive ground-based detectors. It is covered with numerous impact craters reaching up to 326 kilometres (203mi) in diameter, but is less heavily cratered than Oberon, outermost of the five large moons of Uranus. During this period, Galileo gathered a large amount of information about the Jovian system, making close approaches to all of the Galilean moons and finding evidence for thin atmospheres on three of them, as well as the possibility of liquid water beneath the surfaces of Europa, Ganymede, and Callisto. The identification of satellite families is tentative, but the following are typically listed:[43][44][45], The moons of Jupiter are listed below by orbital period. [74] This leads to a volume of Europa's oceans of 31018m3, between two or three times the volume of Earth's oceans. Triton is relatively flat; its observed topography never varies beyond a kilometer. Better data can be obtained from a spacecraft which is orbiting Jupiter, as it can encounter Ganymede at a lower speed and adjust the orbit for a closer approach. Uranus was also examined as part of one trajectory for a precursor interstellar probe concept, Innovative Interstellar Explorer. Theories for this warming include a change of frost patterns on Triton's surface and a change in ice albedo, which would allow more heat to be absorbed. "Sinc During the summer, when the polar temperatures reach as high as 8590K,[5][21] carbon dioxide sublimates and migrates to the opposite pole and to the equatorial regions, giving rise to a type of carbon cycle. However, most planetary scientists conclude that this model considers only those topmost layers of Europa's crust that behave elastically when affected by Jupiter's tides. Historic pioneers who crossed new horizons in the exploration of the Earth, sea and sky. No other spacecraft has ever visited the Uranian system or Titania. ", "Voyager 2 at Neptune: Imaging Science Results", "On the thermal structure of Triton's thermosphere", "Hubble Space Telescope Helps Find Evidence that Neptune's Largest Moon Is Warming Up", "MIT researcher finds evidence of global warming on Neptune's largest moon", "Candidate Cryovolcanic Features in the Outer Solar System", "Triton's Geyser-Like Plumes: Discovery and Basic Characterization", "Gas jet plumes unveil mystery of 'spiders' on Mars", "Working Group for Planetary System Nomenclature", 10.1130/0091-7613(1993)021<0299:DOTARO>2.3.CO;2, "USA.gov: The U.S. Government's Official Web Portal", "Why We Should Use This Jumping Robot to Explore Neptune", "Triton Hopper: Exploring Neptune's Captured Kuiper Belt Object", "Neptune's Moon Triton Is Destination of Proposed NASA Mission", "Neptune Odyssey: Mission to the Neptune-Triton System", https://en.wikipedia.org/w/index.php?title=Triton_(moon)&oldid=1126169751, All Wikipedia articles written in American English, Articles with unsourced statements from December 2022, Creative Commons Attribution-ShareAlike License 3.0, This page was last edited on 7 December 2022, at 22:47. [54] Adopting a Uranian satellite limb darkening profile suggests that the 2004 Hubble size estimate for Quaoar was approximately 40 percent too large, and that a more proper estimate would be about 900km. There are currently two named features on Deimos Swift crater and Voltaire crater after Jonathan Swift and Voltaire who predicted the presence of Martian moons. WebTraditional classification. Several pit chains extend radially from the caldera to the right of the image, while the smaller of the two cryolava lakes is seen to the upper left. WebAriel is the fourth-largest of the Uranian moons, and may have the third-greatest mass.It is also the 14th-largest moon in the Solar System. Ridge, sometimes called a wrinkle ridge e.g. [79] Spectrographic evidence suggests that the darker, reddish streaks and features on Europa's surface may be rich in salts such as magnesium sulfate, deposited by evaporating water that emerged from within. [56] Measurements from the Herschel Space Observatory in 2013 suggested that Quaoar has a diameter of 1,070km (660mi). How to say Ban-Ki-Moon in English? [29] However, the present knowledge of Titania's geological evolution is quite limited. This source of internal heat disappeared following tidal locking and circularization of the orbit. Used on Venus, Io, Titan, and Mars. The bright, slightly pinkish, south polar cap at bottom is composed of nitrogen and methane ice and is streaked by dust deposits left by nitrogen gas geysers. With an orbital eccentricity of 0.04, Quaoar follows a nearly circular orbit, only slightly varying in distance from 42AU at perihelion to 45AU at aphelion. Like the famous overestimates of the atmospheric density of Mars, this proved incorrect. "Jupiter II" redirects here. How to say Europa in German? He envisioned that Quaoar was originally covered by a mantle of ice that made it 300km (190mi) to 500km (310mi) bigger than its present size, and that it collided with another Kuiper belt object about twice its sizean object roughly the diameter of Pluto, or even approaching the size of Mars. CO2 geysers on Mars are thought to erupt from its south polar cap each spring in the same way as Triton's geysers. moon pronunciation. The orbits and mean distances of the irregular moons are strongly variable over short timescales due to frequent planetary and solar perturbations,[47] therefore the listed orbital elements of all irregular moons are averaged over a 400-year numerical integration. Viscoelastic damping from tides alone is not thought to be capable of circularizing Triton's orbit in the time since the origin of the system, and gas drag from a prograde debris disc is likely to have played a substantial role. [54] The surface shows deposits of tholins, organic chemical compounds that may be precursors to the origin of life. [49] With an estimated mass greater than 1.61021kg, Quaoar has the mass and diameter "usually" required for being in hydrostatic equilibrium according to the 2006 IAU draft definition of a planet (51020 kg, 800km),[50] and Brown states that Quaoar "must be" a dwarf planet. [57], The Voyager 2 probe observed in 1989 a handful of geyser-like eruptions of nitrogen gas and entrained dust from beneath the surface of Triton in plumes up to 8km high. [104][105][106] It has been suggested that if plumes exist, they are episodic[107] and likely to appear when Europa is at its farthest point from Jupiter, in agreement with tidal force modeling predictions. [92], In addition to the intrinsic magnetic moment, Ganymede has an induced dipole magnetic field. [53] This model was made assuming Quaoar actually had a density of 4.2g/cm3, but more recent estimates have given it a more Pluto-like density of only 2g/cm3, with no further need for the collision theory. L'intero progetto nato da una conversazione che ho avuto con un vicino. [93] Depending on the amount of tilt, the heat generated by the ocean flow could be 100 to thousands of times greater than the heat generated by the flexing of Europa's rocky core in response to gravitational pull from Jupiter and the other moons circling that planet. [28], To ascertain Quaoar's orbit, Brown and Trujillo initiated a search for archival precovery images. There are currently no named features on Uranian small satellites, however the naming convention is heroines from plays by Shakespeare and Pope. [34] Triton's reddish color is thought to be the result of methane ice, which is converted to tholins under exposure to ultraviolet radiation. Little is known about the north pole because it was on the night side during the Voyager 2 encounter, but it is thought that Triton must also have a north polar ice cap. In the early 2000s, Jupiter Europa Orbiter led by NASA and the Jupiter Ganymede Orbiter led by the ESA were proposed together as an Outer Planet Flagship Mission to Jupiter's icy moons called Europa Jupiter System Mission, with a planned launch in 2020. [77] The current heat flux out of Ganymede is probably higher than that out of Callisto.[97]. [108] Additional imaging evidence from the Hubble Space Telescope was presented in September 2016. The mean density is 2.061g/cm3,[6] reflecting a composition of approximately 1535% water ice. [58] Although commonly termed "cryovolcanic", this nitrogen plume activity is distinct from Triton's larger scale cryovolcanic eruptions, as well as volcanic processes on other worlds, which are powered by internal heat. These include:[3]. It is theorized that because of radioactive and tidal heating (as mentioned in the sections above), there are points in the depths of Europa's ocean that may only be slightly cooler than that of Earth's oceans. However, the first certain observations of Jupiter's satellites were those of Galileo Galilei in 1609. [162][163], Another proposal put forward in 2001 calls for a large nuclear-powered "melt probe" (cryobot) that would melt through the ice until it reached an ocean below. [21][22][23][24] Such plume activity could help researchers in a search for life from the subsurface Europan ocean without having to land on the moon. It has been speculated that there will be several more future missions to Europa in hopes of further studying the atmosphere, chemical composition, and possibility of extraterrestrial life below the icy surface.[131]. The process lasted for about 200million years,[37] implying that any endogenous activity ceased billions of years ago.[7]. WebIapetus (/ a p t s /) is a moon of Saturn.It is the 24th of Saturns 83 known moons. [22], Given that Ganymede is completely differentiated and has a metallic core,[8][77] its intrinsic magnetic field is probably generated in a similar fashion to the Earth's: as a result of conducting material moving in the interior. [47] A 2006 model of internal heating via radioactive decay suggested that Quaoar may not be capable of sustaining an internal ocean of liquid water at the mantlecore boundary. These features are assigned names which are Latin terms describing weather and other abstract concepts. [77] The heat being released from its core and silicate mantle enables the subsurface ocean to exist,[45] whereas the slow cooling of the liquid FeFeS core causes convection and supports magnetic field generation. As it continues to move, the hydrogen is light enough to pass through the surface gravity of the atmosphere leaving behind only oxygen. [1][10] He later reported the discoveries of four more satellites,[11] although they were subsequently revealed as spurious. ', Planetary Maps: Visualization and Nomenclature, Development of a Local Toponym System at the Mars Desert Research Station, APTN National News interviews Planetary Cartographer John Koulouris,(Esq.) [91][92]The plasma co-rotating with Jupiter impinges on the trailing side of the Ganymedian magnetosphere much like the solar wind impinges on the Earth's magnetosphere. [55], Europa's most striking surface features are a series of dark streaks crisscrossing the entire globe, called lineae (English: lines). [20] The adjectival form, Titanian, is homonymous with that of Saturn's moon Titan. Break 'iapetus' down into sounds: [EYE] + [AP] + [I] + [TUHS] - say it out loud and exaggerate the sounds until you can consistently produce them. Hollows, irregular steep-sided depressions usually in arrays or clusters. Galileo imaging team members argue for the existence of a subsurface ocean from analysis of Voyager and Galileo images. [38] However, subsequent even larger discoveries such as 136199 Eris were simply numbered according to the order in which their orbits were confirmed. [37] These flybys were denoted G1, G2, G7, G8, G28 and G29. [57] More precise observations of Quaoar's near infrared spectrum in 2007 indicated the presence of small quantities (5%) of solid methane and ethane. Pronunciation of Europa with 4 audio pronunciations, 1 synonym, 1 meaning, 6 translations, 17 sentences and more for Europa. A flat-topped prominence with cliff-like edges, i.e. Authors and artists associated with space exploration, especially Pluto and the Kuiper Belt. [19], Triton is named after the Greek sea god Triton (), the son of Poseidon (the Greek god corresponding to the Roman Neptune). [32][36] Despite this, the name was approved by the CSBN, and the naming citation, along with Quaoar's official numbering, was published in a Minor Planet Circular on 20 November 2002. [28] The naming scheme was suggested by Simon Marius,[29] who attributed the proposal to Johannes Kepler:[29][30]. After measuring Quaoar's size with the Hubble Space Telescope in July, the team began considering names for the object, particularly those from New World mythologies. [106] Pioneer 10's closest approach was 446,250km, about 85 times Ganymede's diameter. [65] There are long double ridges of ice with central troughs bearing a strong resemblance to Europan lineae (although they have a larger scale[14]), and which may have a similar origin,[7] possibly shear heating from strike-slip motion along faults caused by diurnal tidal stresses experienced before Triton's orbit was fully circularized. [60][61][62] Quaoar has been chosen as a flyby target for missions like these particularly for its escaping methane atmosphere and possible cryovolcanism, as well as its close proximity to the heliospheric nose.[60]. Molecular hydrogen never reaches the surface, as it is light enough to escape Europa's surface gravity. Once every 42 years, when Uranus has an equinox and its equatorial plane intersects the Earth, mutual occultations of Uranus's moons become possible. There is only one named feature on Thebe Zethus Crater. It may have undergone an early endogenic resurfacing event which obliterated its older, heavily cratered surface. The most plausible candidate for this role is a large subsurface ocean of liquid saltwater. The science questions motivating this prioritization include questions about the Uranian satellites' bulk properties, internal structure, and geologic history. [10], The slight eccentricity of Europa's orbit, maintained by the gravitational disturbances from the other Galileans, causes Europa's sub-Jovian point to oscillate around a mean position. So far the only close-up images of Titania have been from the Voyager 2 probe, which photographed the moon during its flyby of Uranus in January 1986. [g] Titania's orbit has a small eccentricity and is inclined very little relative to the equator of Uranus. If the ice shell of Europa is really only a few kilometers thick, this "thin ice" model would mean that regular contact of the liquid interior with the surface could occur through open ridges, causing the formation of areas of chaotic terrain. [24] In particular, they had also found two archival photographic plates taken by astronomer Charles T. Kowal in May 1983,[27] who at the time was searching for the hypothesized Planet X at the Palomar Observatory. 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