"fragments of a single planet was gradually abandoned over the course of the middle decades of the 20th century in favor of the conclusion that no planet had ever accreted in the region of the asteroid belt in the first place. In fiction, various other names were given to the same or similar concepts. Fictional planets in our Solar System beyond the orbit of Neptune have been employed many times as settings or references in science fiction. Following the general reception of Pluto as the ninth planet of the Solar System in 1930, a hypothetical additional planet was sometimes called"
"Despina (moon) Despina ( or ; Latin: ""Despœna""; Greek: ""Δέσποινα""), also known as Neptune V, is the third-closest inner satellite of Neptune. It is named after Greek mythological character Despoina, a nymph who was a daughter of Poseidon and Demeter. Despina was discovered in late July 1989 from the images taken by the ""Voyager 2"" probe. It was given the temporary designation S/1989 N 3. The discovery was announced (IAUC 4824) on August 2, 1989, but the text only talks of ""10 frames taken over 5 days"", giving a discovery date of sometime before July 28. The name was given"
"ring upon passing its Roche limit due to tidal stretching. The diameter of Despina is approximately . Despina (moon) Despina ( or ; Latin: ""Despœna""; Greek: ""Δέσποινα""), also known as Neptune V, is the third-closest inner satellite of Neptune. It is named after Greek mythological character Despoina, a nymph who was a daughter of Poseidon and Demeter. Despina was discovered in late July 1989 from the images taken by the ""Voyager 2"" probe. It was given the temporary designation S/1989 N 3. The discovery was announced (IAUC 4824) on August 2, 1989, but the text only talks of ""10 frames"
"Proteus (moon) Proteus ( ; Greek: ""Πρωτεύς""), also known as Neptune VIII, is the second-largest Neptunian moon, and Neptune's largest inner satellite. Discovered by ""Voyager 2"" spacecraft in 1989, it is named after Proteus, the shape-changing sea god of Greek mythology. Proteus orbits Neptune in a nearly equatorial orbit at the distance of about 4.75 equatorial radii of the planet. Despite being a predominantly icy body more than 400 km in diameter, Proteus's shape deviates significantly from an ellipsoid. It is shaped more like an irregular polyhedron with several slightly concave facets and relief as high as 20 km. Its"
"Desdemona (moon) Desdemona ( ) is an inner satellite of Uranus. It was discovered from the images taken by ""Voyager 2"" on 13 January 1986, and was given the temporary designation S/1986 U 6. Desdemona is named after the wife of Othello in William Shakespeare's play ""Othello"". It is also designated Uranus X. Desdemona belongs to Portia Group of satellites, which also includes Bianca, Cressida, Juliet, Portia, Rosalind, Cupid, Belinda and Perdita. These satellites have similar orbits and photometric properties. Other than its orbit, radius of 32 km and geometric albedo of 0.08 virtually nothing is known about Desdemona. At"
"""Voyager 2"" discovered six moons of Neptune. Of these, the irregularly shaped Proteus is notable for being as large as a body of its density can be without being pulled into a spherical shape by its own gravity. Although the second-most-massive Neptunian moon, it is only 0.25% the mass of Triton. Neptune's innermost four moons—Naiad, Thalassa, Despina and Galatea—orbit close enough to be within Neptune's rings. The next-farthest out, Larissa, was originally discovered in 1981 when it had occulted a star. This occultation had been attributed to ring arcs, but when ""Voyager 2"" observed Neptune in 1989, Larissa was found"
"on 16 September 1991. Despina is irregularly shaped and shows no sign of any geological modification. It is likely that it is a rubble pile re-accreted from fragments of Neptune's original satellites, which were smashed up by perturbations from Triton soon after that moon's capture into a very eccentric initial orbit. Despina's orbit lies close to but outside of the orbit of Thalassa and just inside the Le Verrier ring. As it is also below Neptune's synchronous orbit radius, it is slowly spiralling inward due to tidal deceleration and may eventually impact Neptune's atmosphere, or break up into a planetary"
"to the planet. Proteus is the second-largest moon of Neptune. It is about 420 kilometres in diameter, larger than Nereid, the second to be discovered. It was not discovered by Earth-based telescopes because it is so close to Neptune that it is lost in the glare of reflected sunlight. The surface of Proteus is dark—its geometrical albedo is about 10%. The color of its surface is neutral as the reflectivity does not change appreciably with the wavelength from violet to green. In the near-infrared around 2 μm Proteus's surface becomes less reflective, pointing to a possible presence of complex organic"
"Deimos and Phobos Interior Explorer Deimos and Phobos Interior Explorer (DePhine) is a European mission concept to use a dedicated orbiter to explore the two Moons of Mars: Phobos and Deimos. The mission concept was proposed in 2016 to the European Space Agency's Cosmic Vision programme for launch in 2030, but it was not chosen as a finalist for the M5 mission class. DePhine was proposed in 2016 to ESA's Cosmic Vision programme as an M-class (medium class) mission for launch in 2030 as the M5 mission. It was proposed by the Institute of Planetary Research of the German Aerospace"
"the Voyager 2 images Desdemona appears as an elongated object, the major axis pointing towards Uranus. The ratio of axes of Desdemona's prolate spheroid is 0.6 ± 0.3. Its surface is grey in color. Desdemona may collide with one of its neighboring moons Cressida or Juliet within the next 100 million years. Explanatory notes Citations Desdemona (moon) Desdemona ( ) is an inner satellite of Uranus. It was discovered from the images taken by ""Voyager 2"" on 13 January 1986, and was given the temporary designation S/1986 U 6. Desdemona is named after the wife of Othello in William Shakespeare's"
"an inclination of 0° with respect to the ecliptic. The body's observation arc begins six days prior to its official discovery observation in April 1999. It is a cubewano from the classical Kuiper belt, located in between the resonant plutino and twotino populations and has a low-eccentricity orbit. With its very small inclination (0.3°), significantly less than 4–7°, the object belongs to the cold population rather than the ""stirred"" hot population. This minor planet was named from Greek mythology after Deucalion, son of Prometheus. He and his wife Pyrrha were the only ones that survived the great deluge (""the flood"
"On February 19, 2008, a 10.3 Jupiter mass extrasolar planet was found to be orbiting the star. 18 Delphini 18 Delphini (abbreviated 18 Del), also named Musica, is a yellow giant star approximately 238 light-years from Earth in the constellation of Delphinus of the low northern hemisphere. An object believed to be an extrasolar planet (designated 18 Delphini b or Arion) orbits the star. 18 Delphini is the star's Flamsteed designation. Following its discovery the planet was designated 18 Delphini b. In July 2014 the International Astronomical Union launched a process for giving proper names to certain exoplanets and their"
"thousand minor planets. ""Prometheus"" orbits the Sun in the outer main-belt at a distance of 2.6–3.2 AU once every 5.00 years (1,827 days). Its orbit has an eccentricity of 0.10 and an inclination of 3° with respect to the ecliptic. According to the surveys carried out by NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, ""Prometheus"" measures 14.2 kilometers in diameter, and its surface has an albedo of 0.126. As of 2017, its spectral type, rotation period and shape remain unknown. This minor planet was named for Prometheus, a Titan from Greek mythology, who stole the fire from"
"666 Desdemona 666 Desdemona, provisional designation , is a stony asteroid from the middle region of the asteroid belt, approximately 29 kilometers in diameter. It was discovered on 23 July 1908, by German astronomer August Kopff at Heidelberg Observatory in southern Germany, and named after Desdemona, character in Shakespeare's ""The Tragedy of Othello, the Moor of Venice"". ""Desdemona"" is a stony S-type asteroid that orbits the Sun in the middle main-belt at a distance of 2.0–3.2 AU once every 4 years and 2 months (1,525 days). Its orbit has an eccentricity of 0.24 and an inclination of 8° with respect"
"compounds such as hydrocarbons or cyanides. These compounds may be responsible for the low albedo of the inner Neptunian moons. Although Proteus is usually thought to contain significant amounts of water ice, it has not been detected spectroscopically on the surface. The shape of Proteus is close to a sphere with a radius of about 210 km, although deviations from the spherical shape are large—up to 20 km; scientists believe it is about as large as a body of its density can be without being pulled into a perfect spherical shape by its own gravity. Saturn's moon Mimas has an"
"Lysithea (moon) Lysithea ( , ; ) is a prograde irregular satellite of Jupiter. It was discovered by Seth Barnes Nicholson in 1938 at Mount Wilson Observatory and is named after the mythological Lysithea, daughter of Oceanus and one of Zeus' lovers. Lysithea did not receive its present name until 1975; before then, it was simply known as . It was sometimes called ""Demeter"" from 1955 to 1975. It belongs to the Himalia group, five moons orbiting between 11 and 13 Gm from Jupiter at an inclination of about 28.3°. Its orbital elements are as of January 2000. They are"
"announced its discovery on July 7, 1989, speaking only of ""17 frames taken over 21 days"", which gives a discovery date of sometime before June 16. On 16 September 1991 S/1989 N 1 was named after Proteus, the shape-changing sea god of Greek mythology. Proteus orbits Neptune at the distance approximately equal to 4.75 equatorial radii of the planet. Its orbit has a small eccentricity and is inclined by about 0.5° to the planet's equator. Proteus is the largest of the regular prograde satellites of Neptune. It rotates synchronously with the orbital motion, which means that one face always points"
"DENIS J082303.1-491201 DENIS-P J082303.1-491201 (also known as DENIS J082303.1-491201, DE0823-49), is a binary system of two brown dwarfs, located away from the Earth. The system is located in the constellation Vela. The primary has a spectral class of L1.5, a mass of and a temperature of . The secondary is also a brown dwarf but with a spectral type of L5.5, a mass of , and a temperature of . The mass ratio is around 0.64 to 0.74. The system has an orbital period of 248 days. The age of the system is estimated to be around 80 to 500"
"26 Proserpina Proserpina (minor planet designation: 26 Proserpina) is a main-belt asteroid discovered by R. Luther on May 5, 1853. It is named after the Roman goddess Proserpina, the daughter of Ceres and the Queen of the Underworld. Photometric observations of this asteroid have produced discrepant estimates of the rotation period. A period of 12.13 hours was reported in 1979, followed by 10.6 hours in 1981 and 6.67 hours in 2001. Observations made in 2007 at the Oakley Observatory in Terre Haute, Indiana produced a light curve with a period of 13.06 ± 0.03 hours and a brightness variation of"
"continuously changing due to solar and planetary perturbations. Lysithea (moon) Lysithea ( , ; ) is a prograde irregular satellite of Jupiter. It was discovered by Seth Barnes Nicholson in 1938 at Mount Wilson Observatory and is named after the mythological Lysithea, daughter of Oceanus and one of Zeus' lovers. Lysithea did not receive its present name until 1975; before then, it was simply known as . It was sometimes called ""Demeter"" from 1955 to 1975. It belongs to the Himalia group, five moons orbiting between 11 and 13 Gm from Jupiter at an inclination of about 28.3°. Its orbital"
"DENIS-P J082303.1-491201 b DENIS-P J082303.1-491201 b (alias 2MASS J08230313-4912012 b) is a substellar object, classified as either an exoplanet or a brown dwarf, orbiting DENIS-P J082303.1-491201, an L1.5-type brown dwarf in the constellation Vela. was discovered by Sahlmann et al. (2013) using the ESO telescopes at the La Silla Paranal Observatory. It is part of an ultracool binary system. is located from Earth. At , it is listed as the second most massive planet in the NASA Exoplanet Archive. orbits the nearby L1.5-type brown dwarf , which is % the mass of our Sun, and has an orbital period of"
"moons of Jupiter. Two asteroids share the same names as moons of Neptune: 74 Galatea and 1162 Larissa. The moons of Neptune can be divided into two groups: regular and irregular. The first group includes the seven inner moons, which follow circular prograde orbits lying in the equatorial plane of Neptune. The second group consists of all seven other moons including Triton. They generally follow inclined eccentric and often retrograde orbits far from Neptune; the only exception is Triton, which orbits close to the planet following a circular orbit, though retrograde and inclined. In order of distance from Neptune, the"
"apparent magnitude of Deimos is 12.45. Only two geological features on Deimos have been given names. The craters Swift and Voltaire are named after writers who speculated on the existence of two Martian moons before Phobos and Deimos were discovered. DEIMOS Deimos's orbit is nearly circular and is close to Mars's equatorial plane. Deimos is possibly an asteroid that was perturbed by Jupiter into an orbit that allowed it to be captured by Mars, though this hypothesis is still controversial and disputed. Both Deimos and Phobos have very circular orbits which lie almost exactly in Mars' equatorial plane, and hence"
"could be released in front of the spacecraft during the descent maneuver and then resulting in a densification of the atmosphere just in front of the spacecraft. Deimos (moon) Deimos (systematic designation: Mars II) is the smaller and outermost of the two natural satellites of the planet Mars, the other being Phobos. Deimos has a mean radius of and takes 30.3 hours to orbit Mars. Deimos is from Mars, much further than Mars's other moon, Phobos. It is named for Deimos who in Greek mythology is the twin brother of Phobos, and personifies terror. Deimos was discovered by Asaph Hall,"
"due to tidal stretching. Relatively soon after, the spreading debris may impinge upon Despina's orbit. Thalassa (moon) Thalassa ( ; Greek: ""Θάλασσα""), also known as Neptune IV, is the second-innermost satellite of Neptune. Thalassa was named after sea goddess Thalassa, a daughter of Aether and Hemera from Greek mythology. ""Thalassa"" is also the Greek word for ""sea"". Thalassa was discovered sometime before mid-September 1989 from the images taken by the ""Voyager 2"" probe. It was given the temporary designation S/1989 N 5. The discovery was announced (IAUC 4867) on September 29, 1989, but the text only talks of ""25 frames"
"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"
"rises an hour before the ""Dog Star"", Sirius, of Canis Major. It is a binary star system, consisting of a yellow-white main sequence star of spectral type F5 IV-V, named Procyon A, and a faint white dwarf companion of spectral type DA, named Procyon B. Procyon B, which orbits the more massive star every 41 years, is of magnitude 10.7. Procyon A is 1.4 times the Sun's mass, while its smaller companion is 0.6 times as massive as the Sun. The system is from Earth, the shortest distance to a northern-hemisphere star of the first magnitude. Gomeisa, or Beta Canis"
"Pegasus the flying horse. Delphinus lacks stars above fourth (apparent) magnitude; its brightest star is of magnitude 3.8. The main asterism in Delphinus is Job's Coffin, nearly a 45°-apex lozenge diamond of the four brightest stars: Alpha, Beta, Gamma, and Delta Delphini. Delphinus is in a rich Milky Way star field. Alpha and Beta Delphini have 19th century names Sualocin and Rotanev, read backwards: Nicolaus Venator, the Latinized name of a Palermo Observatory director, Niccolò Cacciatore (d. 1841). Alpha Delphini is a blue-white hued main sequence star of magnitude 3.8, 241 light-years from Earth. Beta Delphini, called Rotanev. The gap"
"Roman god of the underworld's traditional Latin name, Dis. Venus, in order to bring love to Pluto, sent her son Amor (also known as Cupid) to hit Pluto with one of his arrows. Proserpina was in Sicily, at the Pergusa Lake near Enna, where she was playing with some nymphs and collecting flowers, when Pluto came out from the volcano Etna with four black horses named Orphnaeus, Aethon, Nycteus and Alastor. He abducted her in order to marry her and live with her in the underworld of which he was the ruler. Her mother Ceres, also known as Demeter, the"
"Prometheus (moon) Prometheus is an inner satellite of Saturn. It was discovered in 1980 (some time before October 25) from photos taken by the ""Voyager 1"" probe, and was provisionally designated . In late 1985 it was officially named after Prometheus, a Titan in Greek mythology. It is also designated (16). Pronunciation for ""Prometheus"" is , ; Greek: ""Προμηθεύς"". Prometheus is extremely elongated, measuring approximately . It has several ridges and valleys and a number of impact craters of about diameter are visible, but it is less cratered than nearby Pandora, Epimetheus, and Janus. From its very low density and"
"18 Delphini 18 Delphini (abbreviated 18 Del), also named Musica, is a yellow giant star approximately 238 light-years from Earth in the constellation of Delphinus of the low northern hemisphere. An object believed to be an extrasolar planet (designated 18 Delphini b or Arion) orbits the star. 18 Delphini is the star's Flamsteed designation. Following its discovery the planet was designated 18 Delphini b. In July 2014 the International Astronomical Union launched a process for giving proper names to certain exoplanets and their host stars. The process involved public nomination and voting for the new names. In December 2015, the"
"Dysnomia (moon) Dysnomia (Greek: ""Δυσνομία"")—officially (136199) Eris I Dysnomia—is the only known moon of the dwarf planet Eris (the most massive known dwarf planet in the Solar System). It was discovered in 2005 by Mike Brown and the laser guide star adaptive optics team at the W. M. Keck Observatory, and carried the provisional designation of until officially named ""Dysnomia"" (from the Ancient Greek word meaning anarchy/lawlessness) after the daughter of the Greek goddess Eris. During 2005, the adaptive optics team at the Keck telescopes in Hawaii carried out observations of the four brightest Kuiper belt objects (Pluto, , ,"
"about 246 days. DENIS-P J082303.1-491201 b DENIS-P J082303.1-491201 b (alias 2MASS J08230313-4912012 b) is a substellar object, classified as either an exoplanet or a brown dwarf, orbiting DENIS-P J082303.1-491201, an L1.5-type brown dwarf in the constellation Vela. was discovered by Sahlmann et al. (2013) using the ESO telescopes at the La Silla Paranal Observatory. It is part of an ultracool binary system. is located from Earth. At , it is listed as the second most massive planet in the NASA Exoplanet Archive. orbits the nearby L1.5-type brown dwarf , which is % the mass of our Sun, and has an"