"imagery, and sorted by volume. Some omitted objects are larger than the ones included here, notably Eris, because these have not been imaged in high quality. Solar System The Solar System is the gravitationally bound system of the Sun and the objects that orbit it, either directly or indirectly. Of the objects that orbit the Sun directly, the largest are the eight planets, with the remainder being smaller objects, such as the five dwarf planets and small Solar System bodies. Of the objects that orbit the Sun indirectly—the moons—two are larger than the smallest planet, Mercury. The Solar System formed"
"smallest known planet is PSR B1257+12A, one of the first extrasolar planets discovered, which was found in 1992 in orbit around a pulsar. Its mass is roughly half that of the planet Mercury. The smallest known planet orbiting a main-sequence star other than the Sun is Kepler-37b, with a mass (and radius) slightly higher than that of the Moon. Every planet began its existence in an entirely fluid state; in early formation, the denser, heavier materials sank to the centre, leaving the lighter materials near the surface. Each therefore has a differentiated interior consisting of a dense planetary core surrounded"
"10199 Chariklo 10199 Chariklo ( or ; ; provisional designation ) is the largest confirmed centaur (minor planet of the outer Solar System). It orbits the Sun between Saturn and Uranus, grazing the orbit of Uranus. On 26 March 2014, astronomers announced the discovery of two rings (nicknamed Oiapoque and Chuí) around Chariklo by observing a stellar occultation, making it the first minor planet known to have rings. Chariklo was discovered by James V. Scotti of the Spacewatch program on February 15, 1997. Chariklo is named after the nymph Chariclo (""""), the wife of Chiron and the daughter of Apollo."
"Pluto Pluto (minor planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of bodies beyond Neptune. It was the first Kuiper belt object to be discovered. Pluto was discovered by Clyde Tombaugh in 1930 and was originally considered to be the ninth planet from the Sun. After 1992, its status as a planet was questioned following the discovery of several objects of similar size in the Kuiper belt. In 2005, Eris, a dwarf planet in the scattered disc which is 27% more massive than Pluto, was discovered. This led the International Astronomical Union (IAU) to"
"52872 Okyrhoe 52872 Okyrhoe (; from Greek ""Ωκυρόη, Ωκυρρόη""), provisional designation , is a centaur orbiting in the outer Solar System between Jupiter and Saturn. It was discovered on 19 September 1998, by the Spacewatch survey at Kitt Peak Observatory in Arizona, United States, and named after Ocyrhoe from Greek mythology. Centaurs have short dynamical lives due to strong interactions with the giant planets. ""Okyrhoe"" is estimated to have an orbital half-life of about 670 kiloannum. Of objects listed as a centaur by the Minor Planet Center (MPC), JPL, and the Deep Ecliptic Survey (DES), Okyrhoe has the second smallest"
"coastal borders of Brazil. A request for formal names will be submitted to the IAU at a later date. It has been speculated that 2060 Chiron may have a similar pair of rings. 10199 Chariklo 10199 Chariklo ( or ; ; provisional designation ) is the largest confirmed centaur (minor planet of the outer Solar System). It orbits the Sun between Saturn and Uranus, grazing the orbit of Uranus. On 26 March 2014, astronomers announced the discovery of two rings (nicknamed Oiapoque and Chuí) around Chariklo by observing a stellar occultation, making it the first minor planet known to have"
"camera. This is a 0.61m fork mounted reflecting telescope operating at f/16. This telescope is used exclusively for CCD photometry. It is currently being upgraded and commissioned for robotic use as part of the AAVSO's Robotic Telescope Network. This is the AAVSO's first Southern Hemisphere telescope. This telescope, used exclusively for visual tourist operations is a 0.4m Meade LX200 telescope. In June 2008 it was reported at the meeting of American Astronomical Society that using their new MOA-II telescope, the observatory discovered what is at the time the smallest planet known outside of our Solar System. The planet MOA-2007-BLG-192Lb is"
"Jack Lissauer, a scientist at NASA's Ames Research Center, to conjecture that ""such little planets are common"". Kepler-37b Kepler-37b is an extrasolar planet (exoplanet) orbiting Kepler-37 in the constellation Lyra. it is the smallest planet discovered around a main-sequence star, with a radius slightly greater than that of the Moon. The measurements do not constrain its mass, but masses above a few times that of the Moon give unphysically high densities. Kepler-37b is a sub-Earth, an exoplanet with a radius and mass smaller than Earth. Its surface temperature is . Because of this, it is not expected to have an"
"Kepler-37b Kepler-37b is an extrasolar planet (exoplanet) orbiting Kepler-37 in the constellation Lyra. it is the smallest planet discovered around a main-sequence star, with a radius slightly greater than that of the Moon. The measurements do not constrain its mass, but masses above a few times that of the Moon give unphysically high densities. Kepler-37b is a sub-Earth, an exoplanet with a radius and mass smaller than Earth. Its surface temperature is . Because of this, it is not expected to have an atmosphere. Its radius is approximately 0.34 (about a diameter of ), about a little larger than the"
"into an elliptical orbit, then chemical rockets will fire to deposit the mapper probe into a circular orbit. Both probes will operate for one terrestrial year. The mapper probe carries an array of spectrometers similar to those on ""MESSENGER"", and will study the planet at many different wavelengths including infrared, ultraviolet, X-ray and gamma ray. Mercury (planet) Mercury is the smallest and innermost planet in the Solar System. Its orbital period around the Sun of 87.97 days is the shortest of all the planets in the Solar System. It is named after the Roman deity Mercury, the messenger of the"
"by the mission is Kepler-7b, an extremely low-density exoplanet with less than half the mass of Jupiter, yet nearly 1.5 times the radius. Almost as sparse is Kepler-8b, only slightly more massive and of a similar radius. The Kepler-20 system contains five known planets; three of them are only slightly smaller than Neptune, and two while the other two are some of the first Earth-sized exoplanets to be discovered. Kepler-37 is another star with an exoplanet discovered by Kepler; the planet is the smallest known extrasolar planet known as of February 2013. In April 2013, it was announced that of"
"with a radius and mass smaller than Earth. It has an equilibrium temperature of . It has a radius of 0.54 . This is about the size of Mars, making it the second-smallest exoplanet discovered, with Kepler-37b being the size of the Moon. However, the mass is currently not known, estimates place an upper limit of <4 , the real mass is expected to be significantly lower than this, say around 0.1 , comparable to the size of Kepler-37b. The planet orbits a (K-type) star named Kepler-62, orbited by a total of five planets. The star has a mass of"
"time the smallest known transiting extrasolar planet. The planet is about four thousand kilometers larger in diameter than Uranus and five thousand kilometers larger than Neptune and slightly more massive. Gliese 436b orbits at a distance of four million kilometers or one-fifteenth the average distance of Mercury from the Sun. The planet's surface temperature is estimated from measurements taken as it passes behind the star to be . This temperature is significantly higher than would be expected if the planet were only heated by radiation from its star, which was prior to this measurement, estimated at 520 K. Whatever energy"
"Rings of Chariklo The minor planet and centaur 10199 Chariklo, with a diameter of about , is the smallest celestial object with confirmed rings and the fifth ringed celestial object ever discovered in the Solar System, after the gas giants and ice giants. Orbiting Chariklo is a bright ring system consisting of two narrow and dense bands, 6–7 km (4 mi) and 2–4 km (2 mi) wide, separated by a gap of . The rings orbit at distances of about from the centre of Chariklo, a thousandth the distance between Earth and the Moon. The discovery was made by a"
"obliquely making reference to projections of influences from higher to lower dimensional spaces. Pluto is considered by modern astrologers to be the primary native ruler of the eighth house. Ceres () is the smallest identified dwarf planet in the Solar System, but is significantly the largest object in the asteroid belt. It was discovered on 1 January 1801 by Giuseppe Piazzi, and is named after Ceres, the Roman goddess of growing plants, the harvest, and of motherly love. It was the first asteroid discovered, taking up about one-third of the entire mass of its asteroid belt. The classification of Ceres"
"Until January 2015, Kepler-37 was the smallest star to be measured via asteroseismology. Kepler-37b is the closest planet to the Kepler-37. At the time of its discovery in February 2013, it was the smallest known exoplanet. At in diameter, it is slightly larger than the Moon. It orbits Kepler-37 once every 13 days at a distance of about 0.1 astronomical units (AU). Kepler-37b has a rocky surface and is believed to be too small and too close to its star to support water or maintain an atmosphere. Surface temperature is estimated at . Kepler-37c is around three-quarters of the diameter"
"planet (a super-Earth). Gliese 777 c Gliese 777 c, often catalogued as Gliese 777 Ac or simply HD 190360 c, is an extrasolar planet approximately 52 light-years away in the constellation of Cygnus. The planet was discovered orbiting the primary star of the Gliese 777 system in 2005 using the radial velocity method and confirmed in 2009. The planet was once called the ""smallest extrasolar planet discovered"", but this is currently no longer the case. With a minimum mass just 18 times that of the Earth, the planet is likely a ""hot Neptune"" planet, a small Jovian planet, or possibly"
"observable from the Solar System. Like the other planets of the system, the planet has a high maximum eccentricity of 0.28, but the lowest in that system. Kepler-20e Kepler-20e is an exoplanet orbiting Kepler-20. The planet is notable as it is the first planet with a smaller radius than Earth found orbiting a Sun-like star. The planet is second-closest to the star after Kepler-20b, and at , it is far too hot to have liquid water on its surface. Along with the other four planets in the system, Kepler-20e was announced on 20 December 2011. With a semimajor axis of"
"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"
"solar radii. It is the smallest discovered planet in the Kepler-124 system, and has the closest orbit of the three known planets. Kepler-124b orbits 96% closer to its star than Earth (approximately 3 Earth days), which in the Kepler-124 system is inside the inner limit of the star's habitable zone. Like many Exoplanets discovered by the Kepler telescope, Kepler-124b was found using the transit method. The transit method utilizes the high magnification and numerous instruments on the Kepler telescope to detect slight fluctuations in brightness of a star being observed. These dips can indicate the presence planet and determine certain"
"years. On September 20, 2018, the discovery of an ultra-short period planet was announced, slightly larger than Earth, orbiting the red dwarf LHS 3844. With an orbital period of 11 hours, LHS 3844 b is one of the planets with the shortest known period. It orbits its star at a distance of . LHS 3844 b is also one of the closest known exoplanets to Earth, at a distance of 14.9 parsec. TESS's third discovered exoplanet is HD 202772Ab, a hot Jupiter orbiting the brighter component of the visual binary star HD 202772, located in the constellation Capricornus at a"
"0.07 for a centaur. It has an absolute magnitude of 9.4. This minor planet was named for the Cyllarus, a centaur of Greek mythology. The approved naming citation was published on 14 June 2003 (). 52975 Cyllarus 52975 Cyllarus (), provisionally designated , is a centaur orbiting in the outer Solar System. It was discovered on 12 October 1998, by American astronomer Nichole Danzl at the Kitt Peak National Observatory near Sells, Arizona, in the United States. It was later named after the mythological creature Cyllarus. ""Cyllarus"" orbits the Sun in the outer main-belt at a distance of 16.3–36.0 AU"
"National Observatory in Rio de Janeiro, the Valongo Observatory (at the Federal University of Rio de Janeiro), the Oeste do Paraná State University Observatory or Unioeste (in the state of Paraná), the Pico dos Dias Observatory or OPL (in Minas Gerais) and the São Paulo State University (UNESP – Guaratinguetá) in São Paulo, Rings of Chariklo The minor planet and centaur 10199 Chariklo, with a diameter of about , is the smallest celestial object with confirmed rings and the fifth ringed celestial object ever discovered in the Solar System, after the gas giants and ice giants. Orbiting Chariklo is a"
"is considered one of the smallest known extrasolar planets around a main sequence star, possibly rocky, with a mass around 5.5 times that of the Earth. The orbital radius (assuming a circular orbit) of the planet is 2.6 AU, however the orbital elements are unknown. Based on its low mass and estimated temperature of around 50 K, the planet is thought to consist mainly of ices, like Pluto or Uranus, rather than being a Jupiter-like gas giant. OGLE-2005-BLG-390L OGLE-2005-BLG-390L is a star thought to be a spectral type M (a red dwarf; 95% probability, 4% probability it is a white"
"its star, and is estimated to have a surface temperature of 150 °C, despite the dimness of its star. In 2006, an even smaller exoplanet (only ) was found orbiting the red dwarf OGLE-2005-BLG-390L; it lies 390 million km (2.6 AU) from the star and its surface temperature is −220 °C (53 K). In 2007, a new, potentially habitable exoplanet, Gliese 581c, was found, orbiting Gliese 581. The minimum mass estimated by its discoverers (a team led by Stephane Udry) is . The discoverers estimate its radius to be 1.5 times that of Earth (). Since then Gliese 581d, which"
"System. COROT-7b COROT-7b (previously named COROT-Exo-7b) is an exoplanet orbiting around the star COROT-7, in the constellation Monoceros, at 489 light years from Earth. It was first detected photometrically by the French-led COROT mission and reported in February 2009. Until the announcement of Kepler-10b in January 2011, it was the smallest exoplanet to have its diameter measured, at 1.58 times that of the Earth (which would give it a volume 3.95 times Earth's), and the first potential extrasolar terrestrial planet to be found. The planet has a very short orbital period, revolving around its host star in about 20 hours."
"Gliese 777 c Gliese 777 c, often catalogued as Gliese 777 Ac or simply HD 190360 c, is an extrasolar planet approximately 52 light-years away in the constellation of Cygnus. The planet was discovered orbiting the primary star of the Gliese 777 system in 2005 using the radial velocity method and confirmed in 2009. The planet was once called the ""smallest extrasolar planet discovered"", but this is currently no longer the case. With a minimum mass just 18 times that of the Earth, the planet is likely a ""hot Neptune"" planet, a small Jovian planet, or possibly a large terrestrial"
"two days. Gliese 832 is a red dwarf of spectral type M1.5V and apparent magnitude 8.66 located only 16.1 light-years distant; hence it is one of the nearest stars to the Solar System. A Jupiter-like planet—Gliese 832 b—orbiting the red dwarf over a period of 9.4±0.4 years was discovered in 2008. WISE 2220−3628 is a brown dwarf of spectral type Y, and hence one of the coolest star-like objects known. It has been calculated as being around 26 light-years distant from Earth. Nicknamed the spare-tyre nebula, IC 5148 is a planetary nebula located around 1 degree west of Lambda Gruis."
"as part of the MOA-II gravitational microlensing survey at the Mount John University Observatory in New Zealand. MOA-2007-BLG-192L MOA-2007-BLG-192L is a low-mass red dwarf star or brown dwarf, approximately 3,000 light-years away in the constellation of Sagittarius. It is estimated to have a mass approximately 6% of the Sun's. In 2008, an Earth-sized extrasolar planet was announced to be orbiting this object. The discovery of a planet, MOA-2007-BLG-192Lb, orbiting this object was announced on June 2, 2008. This planet, with a mass of approximately 3.3 times that of Earth, is one of the smallest known extrasolar planets. It was found"
"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"
"and unless there are significant tidal forces when orbiting close to the parent star, sub-Earths also have short periods of geologic activity. Sub-Earth A sub-Earth is a planet ""substantially less massive"" than Earth and Venus. In the Solar System, this category includes Mercury and Mars. Sub-Earth exoplanets are among the most difficult type to detect because their small sizes and masses produce the weakest signal. Despite the difficulty, one of the first exoplanets found was a sub-Earth around a millisecond pulsar PSR B1257+12. The smallest known is WD 1145+017 b with a size of 0.15 Earth radii, or somewhat smaller"
"with a radius and mass bigger than Earth, but smaller than that of the ice giants Neptune and Uranus. It has an equilibrium temperature of . This is hot enough to melt some types of metal. It has a radius of 1.3 , placing it below the estimated radius of ≤1.6 where it would otherwise be a mini-Neptune with a volatile composition, with no solid surface. However, the mass is currently not known, estimates place an upper limit of <9 , the real mass is expected to be significantly lower than this. The planet orbits a (K-type) star named Kepler-62,"
"program describes a fusion-enabled Pluto orbiter and lander based on the Princeton field-reversed configuration reactor. Pluto Pluto (minor planet designation: 134340 Pluto) is a dwarf planet in the Kuiper belt, a ring of bodies beyond Neptune. It was the first Kuiper belt object to be discovered. Pluto was discovered by Clyde Tombaugh in 1930 and was originally considered to be the ninth planet from the Sun. After 1992, its status as a planet was questioned following the discovery of several objects of similar size in the Kuiper belt. In 2005, Eris, a dwarf planet in the scattered disc which is"