"avenge the death of the Amazon-like female warrior Camilla. Diana gives Opis magical weapons for revenge on Camilla's killer, the Etruscan Arruns. Opis sees and laments Camilla's death and shoots Arruns in revenge as directed by Diana. In modern Greek folklore, the term ""nereid"" (, ""neráida"") has come to be used for all nymphs, fairies, or mermaids, not merely nymphs of the sea. Nereid, a moon of the planet Neptune, is named after the Nereids. ""This list is correlated from four sources: Homer's ""Iliad"", Hesiod's ""Theogony"", the ""Bibliotheca"", and Hyginus"""". Because of this, the total number of names goes beyond"
"formed ""in situ"". Triton and Nereid are unusual irregular satellites and are thus treated separately from the other five irregular Neptunian moons, which are more like the outer irregular satellites of the other outer planets. Firstly, they are the largest two known irregular moons in the Solar System, with Triton being almost an order of magnitude larger than all other known irregular moons. Secondly, they both have atypically small semi-major axes, with Triton's being over an order of magnitude smaller than those of all other known irregular moons. Thirdly, they both have unusual orbital eccentricities: Nereid has one of the"
"color, almost like soot. Nereid, though discovered in 1949, still has very little known about it. Triton was revealed as having a remarkably active past. Active geysers and polar caps were discovered and a very thin atmosphere as well, with thin clouds of what is thought to be nitrogen ice particles. At just , it is the coldest known planetary body in the Solar System. The closest approach to Triton was about and it was the last solid world that ""Voyager 2"" explored close-by. Currently there are no approved future missions to visit the Neptunian system. NASA, ESA and independent"
"most eccentric orbits of any known irregular satellite, and Triton's orbit is a nearly perfect circle. Finally, Nereid also has the lowest inclination of any known irregular satellite. Triton follows a retrograde and quasi-circular orbit, and is thought to be a gravitationally captured satellite. It was the second moon in the Solar System that was discovered to have a substantial atmosphere, which is primarily nitrogen with small amounts of methane and carbon monoxide. The pressure on Triton's surface is about 14 μbar. In 1989 the ""Voyager 2"" spacecraft observed what appeared to be clouds and hazes in this thin atmosphere."
"discovery; he later successfully suggested the name Hyperion, previously chosen by John Herschel, for the eighth moon of Saturn when he discovered it. Triton is unique among all large moons in the Solar System for its retrograde orbit around its planet (i.e. it orbits in a direction opposite to the planet's rotation). Most of the outer irregular moons of Jupiter and Saturn also have retrograde orbits, as do some of Uranus's outer moons. However, these moons are all much more distant from their primaries, and are small in comparison; the largest of them (Phoebe) has only 8% of the diameter"
"are Jupiter's Galilean moons (Ganymede, Callisto, Io, and Europa), Saturn's moon Titan, Earth's moon, and Neptune's captured natural satellite Triton. Triton, the smallest of these, has more mass than all smaller natural satellites together. Similarly in the next size group of nine natural satellites, between 1,000 km and 1,600 km across, Titania, Oberon, Rhea, Iapetus, Charon, Ariel, Umbriel, Dione, and Tethys, the smallest, Tethys, has more mass than all smaller natural satellites together. As well as the natural satellites of the various planets, there are also over 80 known natural satellites of the dwarf planets, minor planets and other small"
"only low-amplitude variations (0.033 magnitudes). Thermal modeling based on infrared observations from the Spitzer and Herschel space telescopes suggest that Nereid is only moderately elongated which disfavors forced precession of the rotation. The thermal model also indicates that the surface roughness of Nereid is very high, likely similar to the Saturnian moon Hyperion. Spectrally, Nereid appears neutral in colour and water ice has been detected on its surface. Its spectrum appears to be intermediate between Uranus's moons Titania and Umbriel, which suggests that Nereid's surface is composed of a mixture of water ice and some spectrally neutral material. The spectrum"
"Nereid is only moderately elongated which disfavours forced precession of the rotation. The thermal model also indicates that the surface roughness of Nereid is very high, likely similar to the Saturnian moon Hyperion. Among the remaining irregular moons, Sao and Laomedeia follow prograde orbits, whereas Halimede, Psamathe and Neso follow retrograde orbits. Given the similarity of their orbits, it was suggested that Neso and Psamathe could have a common origin in the break-up of a larger moon. Psamathe and Neso have the largest orbits of any natural satellites discovered in the Solar system to date. They take 25 years to"
"Two moons have significant atmospheres: Saturn's moon Titan and Neptune's moon Triton. A tenuous atmosphere exists around Mercury. The effects of the rotation rate of a planet about its axis can be seen in atmospheric streams and currents. Seen from space, these features show as bands and eddies in the cloud system, and are particularly visible on Jupiter and Saturn. Planetary science frequently makes use of the method of comparison to give a greater understanding of the object of study. This can involve comparing the dense atmospheres of Earth and Saturn's moon Titan, the evolution of outer Solar System objects"
"moon Triton to be investigated around 2029. The proposed ""New Horizons 2"" mission (which was later scrapped) might also have done a close flyby of the Neptunian system. Neptune Neptune is the eighth and farthest known planet from the Sun in the Solar System. In the Solar System, it is the fourth-largest planet by diameter, the third-most-massive planet, and the densest giant planet. Neptune is 17 times the mass of Earth and is slightly more massive than its near-twin Uranus, which is 15 times the mass of Earth and slightly larger than Neptune. Neptune orbits the Sun once every 164.8"
"moons Ariel, Umbriel and Titania. Scientist speculate that the magnetic field of Uranus contributes to the generation of CO2 ice on the surfaces of its moons. Voyager 2 observations of Neptune's moon Triton suggested the presence of dry ice on the surface, though follow up observations indicate that the carbon ices on the surface are carbon monoxide but that the moon's crust is composed of a significant quantity of dry ice. Prolonged exposure to dry ice can cause severe skin damage through frostbite, and the fog produced may also hinder attempts to withdraw from contact in a safe manner. Because"
"into a synchronous rotation, and it is slowly spiralling inward because of tidal acceleration. It will eventually be torn apart, in about 3.6 billion years, when it reaches the Roche limit. In 1989, Triton was the coldest object that had yet been measured in the Solar System, with estimated temperatures of . Neptune's second known satellite (by order of discovery), the irregular moon Nereid, has one of the most eccentric orbits of any satellite in the Solar System. The eccentricity of 0.7512 gives it an apoapsis that is seven times its periapsis distance from Neptune. From July to September 1989,"
"recognition at some time in the future. Alan Stern of the Southwest Research Institute believes the outer planets show signs of collisions with plutoids 1,000 to 2,000 kilometers in diameter: Uranus could have been tipped off its axis by a plutoid, and Triton, the largest moon of Neptune, is probably a captured plutoid from the Kuiper belt. On 24 August 2006, the IAU decided to reclassify Pluto as a dwarf planet, requiring that a planet must ""clear the neighbourhood around its orbit"". The General Assembly of the IAU further resolved: This new category had been proposed under the name """"pluton"""""
"of Poseidon and Amphitrite. The largest moon of Neptune was also named after Triton. The railway station ""Club-Triton"" was officially registered as of December 5, 1968, at the Commission de toponymie du Québec (Geographical Names Board of Québec). Its decimal coordinates are: longitude -72.24389, 47.61306 latitude. Seigneurie du Triton The Seigneurie du Triton is a hunting and fishing outfitter located in the municipality of Lake Edouard, in Upper Batiscanie, in the administrative region of Mauricie, in Canada. The outfitter has exclusive rights to of wilderness, and is a private enterprise accessible only by water. This outfitter territory is part of"
"despite the fact that Triton is more than 4 times as intrinsically bright as our moon and orbits much closer to Neptune. Triton, Neptune's largest moon, has an atmosphere, but it is so thin that its sky is still black, possibly with some pale haze at the horizon. Because Triton orbits with synchronous rotation, Neptune always appears in the same position in its sky. Triton's rotation axis is inclined 130° to Neptune's orbital plane and thus points within 40° of the Sun twice per Neptunian year, much like Uranus's. As Neptune orbits the Sun, Triton's polar regions take turns facing"
"nitrogen, a mostly water-ice crust, an icy mantle and a substantial core of rock and metal. The core makes up two-thirds of its total mass. The mean density is 2.061 g/cm reflecting a composition of approximately 15–35% water ice. 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 terrains suggest a complex geological history. Part of its surface has geysers erupting sublimated nitrogen gas,"
"god Neptune's trident. Neptune is not visible to the unaided eye and is the only planet in the Solar System found by mathematical prediction rather than by empirical observation. Unexpected changes in the orbit of Uranus led Alexis Bouvard to deduce that its orbit was subject to gravitational perturbation by an unknown planet. Neptune was subsequently observed with a telescope on 23 September 1846 by Johann Galle within a degree of the position predicted by Urbain Le Verrier. Its largest moon, Triton, was discovered shortly thereafter, though none of the planet's remaining known 13 moons were located telescopically until the"
"Triton Hopper Triton Hopper is a proposed NASA lander to Triton, the largest moon of Neptune. The idea is to harvest the abundant nitrogen ice on the surface of Triton and use it as propellant for multiple short flights and explore a variety of locations. The concept transitioned in March 2018 to Phase II to refine their designs and explore aspects of implementing the new technology. Triton is the largest moon of Neptune. In 1989, ""Voyager 2"" flew past the moon at a distance of 40,000 km, and discovered several cryovolcanoes on its surface. Triton is geologically active; its surface"
"oxygen and sulfur from the tenuous atmosphere of Jupiter's volcanic moon, Io and other objects including Jupiter and Europa. A torus of oxygen and hydrogen produced by Saturn's moon, Enceladus forms part of the E ring around Saturn. Nitrogen gas transfer between Pluto and Charon has also been modelled and is expected to be observable by the New Horizons space probe. Similar tori produced by Saturn's moon Titan (nitrogen) and Neptune's moon Triton (hydrogen) is predicted. Complex magnetic interactions have been observed in satellite systems. Most notably, the interaction of Jupiter's strong magnetic field with those of Ganymede and Io."
"which rises to the upper atmosphere. Studies by Grundy et al. (2006) indicate active carbon cycles operates on Titania, Umbriel and Ariel and Oberon through the ongoing sublimation and deposition of carbon dioxide, though some is lost to space over long periods of time. Neptune's internal heat and convection drives cycles of methane, carbon, and a combination of other volatiles within Triton's lithosphere. Models predicted the presence of seasonal nitrogen cycles on the moon Triton, however this has not been supported by observations to date. Models predict a seasonal nitrogen cycle on Pluto and observations by New Horizons appear to"
"to accumulate from space as interplanetary dust. The extensive dark areas on the trailing hemisphere of Saturn's moon Rhea are thought to be deposited tholins. Neptune's moon Triton is observed to have the reddish color characteristic of tholins. Triton's atmosphere is mostly nitrogen, with trace amounts of methane and carbon monoxide. Tholins occur on the dwarf planet Pluto and are responsible for red colors as well as the blue tint of the atmosphere of Pluto. The reddish-brown cap of the north pole of Charon, the largest of five moons of Pluto, is thought to be composed of tholins, produced from"
"for newly discovered Neptunian moons is to accord with these first two choices by naming them after Greek sea deities. Neptune XIV, the most recently discovered Neptunian moon, was given a Roman numeral but not a name. The name of Pluto's moon Charon was suggested by James W. Christy, its discoverer, soon after its discovery. The other four moons are named Hydra, Nix, Kerberos, and Styx. Charon, Hydra, Nix, and Kerberos are all characters in Greek mythology, with ties to Hades (the Greek equivalent of Pluto). Charon ferries the dead across the River Acheron, Hydra guards the waters of the"
"Moons of Pluto The dwarf planet Pluto has five moons down to a detection limit of about 1 km in diameter. In order of distance from Pluto, they are Charon, Styx, Nix, Kerberos, and Hydra. Charon, the largest of the five moons, is mutually tidally locked with Pluto, and is massive enough that Pluto–Charon is sometimes considered a double dwarf planet. The innermost and largest moon, Charon, was discovered by James Christy on 22 June 1978, nearly half a century after Pluto was discovered. This led to a substantial revision in estimates of Pluto's size, which had previously assumed that"
"orbit and is believed to be a former regular satellite that was scattered to its current orbit through gravitational interactions during Triton's capture. Water ice has been spectroscopically detected on its surface. Early measurements of Nereid showed large, irregular variations in its visible magnitude, which were speculated to be caused by forced precession or chaotic rotation combined with an elongated shape and bright or dark spots on the surface. This was disproved in 2016, when observations from the Kepler space telescope showed only minor variations. Thermal modeling based on infrared observations from the Spitzer and Herschel space telescopes suggest that"
"the Sun for 82 years at a stretch, resulting in radical seasonal changes as one pole, then the other, moves into the sunlight. Neptune itself would span 8 degrees in Triton's sky, though with a maximum brightness roughly comparable to that of the full moon on Earth it would appear only about as bright as the full moon, per unit area. Due to its eccentric orbit, Nereid would vary considerably in brightness, from fifth to first magnitude; its disk would be far too small to see with the naked eye. Proteus would also be difficult to resolve at just 5–6"
"Solid nitrogen is used as a matrix on which to store and study reactive chemical species, such as free radicals or isolated atoms. One use is to study dinitrogen complexes of metals in isolation from other molecules. Solid nitrogen forms a large part of the surface of Pluto and the Neptunian moon Triton. On Pluto it was directly observed for the first time in July 2015 by the ""New Horizons"" space probe and on Triton it was directly observed by the ""Voyager 2"" space probe in August 1989. On Triton, solid nitrogen takes the form of frost crystals and a"
"of a tidal lock. Charon is a relatively large moon in comparison to its primary and also has a very close orbit. This results in Pluto and Charon being mutually tidally locked. Pluto's other moons are not tidally locked; Styx, Nix, Kerberos, and Hydra all rotate chaotically due to the influence of Charon. The tidal locking situation for asteroid moons is largely unknown, but closely orbiting binaries are expected to be tidally locked, as well as contact binaries. The Moon's rotation and orbital periods are tidally locked with each other, so no matter when the Moon is observed from Earth"
"sea level. The low temperatures and higher gravity of the Solar System's giant planets—Jupiter, Saturn, Uranus and Neptune—allow them more readily to retain gases with low molecular masses. These planets have hydrogen–helium atmospheres, with trace amounts of more complex compounds. Two satellites of the outer planets possess significant atmospheres. Titan, a moon of Saturn, and Triton, a moon of Neptune, have atmospheres mainly of nitrogen. When in the part of its orbit closest to the Sun, Pluto has an atmosphere of nitrogen and methane similar to Triton's, but these gases are frozen when it is farther from the Sun. Other"
"can be seen in the adjacent picture contributes to the moon's anti-greenhouse effect and lowers the temperature by reflecting sunlight away from the satellite. The thick atmosphere blocks most visible wavelength light from the Sun and other sources from reaching Titan's surface. Triton, Neptune's largest moon, has a tenuous nitrogen atmosphere with small amounts of methane. Tritonian atmospheric pressure is about 1Pa. The surface temperature is at least 35.6 K, with the nitrogen atmosphere in equilibrium with nitrogen ice on Triton's surface. Triton has increased in absolute temperature by 5% since 1989 to 1998. A similar rise of temperature on"
"Neptune's moon Triton, orbit near the equatorial plane. He concluded that these moons formed from equatorial accretion disks. But he found that our moon, although it was once inside the critical distance from the earth, never had an equatorial orbit as would be expected from various scenarios for its origin. This is called the lunar inclination problem, to which various solutions have since been proposed. For planets and other rotating celestial bodies, the angle of the equatorial plane relative to the orbital plane — such as the tilt of the Earth's poles toward or away from the Sun — is"
"its orbit around Neptune: it keeps one face oriented toward the planet at all times. Its equator is almost exactly aligned with its orbital plane. At the present time, Triton's rotational axis is about 40° from Neptune's orbital plane, and hence at some point during Neptune's year each pole points fairly close to the Sun, almost like the poles of Uranus. As Neptune orbits the Sun, Triton's polar regions take turns facing the Sun, resulting in seasonal changes as one pole, then the other, moves into the sunlight. Such changes were observed in 2010. Triton's revolution around Neptune has become"
"it during its 1989 flyby, due to its dimness. Given that the relevant images have long been available to the public, the discovery could have been made by anyone. Neptune XIV is the first moon of Neptune to be discovered since September 2003, when Psamathe was discovered. Neptune's largest moon, Triton, has a retrograde and inclined orbit. It is hypothesized that Neptune captured it from the Kuiper belt well after Neptune's original satellite system formed. The pre-existing moons' orbits would have been shifted by this event, leading to the ejection of some moons and the collisional destruction of others. Neptune's"
"close fly-by of Triton, the larger of Neptune's two originally known moons, passing within about 40,000 kilometers (25,000 mi). ""Voyager 2"" discovered previously unknown Neptunian rings, and confirmed six new moons: Despina, Galatea, Larissa, Proteus, Naiad and Thalassa. While in the neighborhood of Neptune, ""Voyager 2"" discovered the ""Great Dark Spot"", which has since disappeared, according to observations by the Hubble Space Telescope. The Great Dark Spot was later hypothesized to be a region of clear gas, forming a window in the planet's high-altitude methane cloud deck. With the decision of the International Astronomical Union to reclassify Pluto as a"