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List Of Solar System Objects
The following is a list of Solar System objects by orbit, ordered by increasing distance from the Sun. Most named objects in this list have a diameter of 500 km or more. *The Sun, a spectral class G2V main-sequence star *The inner Solar System and the terrestrial planets ** Mercury *** Mercury-crossing minor planets **Venus *** Venus-crossing minor planets **** 524522 Zoozve, Venus' quasi-satellite **Earth ***Moon ***Near-Earth asteroids **** **** 99942 Apophis **** 433 Eros ***Earth trojans () *** Earth-crosser asteroids ****Earth's quasi-satellites **Mars *** Deimos *** Phobos ***Mars trojans *** Mars-crossing minor planets **Asteroids in the asteroid belt, between the orbits of Mars and Jupiter *** Ceres, a dwarf planet ***Pallas *** Vesta *** Hygiea ***Asteroids number in the hundreds of thousands. For longer lists, see list of exceptional asteroids, list of asteroids, or list of Solar System objects by size. **** Asteroid moons **A number of smaller groups distinct f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth Trojan
An Earth trojan is an asteroid that orbits the Sun in the vicinity of the Earth–Sun Lagrange points (leading 60°) or (trailing 60°), thus having an orbit similar to Earth's. Only two Earth trojans have so far been discovered. The name "trojan" was first used in 1906 for the Jupiter trojans, the asteroids that were observed near the Lagrangian points of Jupiter's orbit. Members (leading) * : A 300-metre diameter asteroid, discovered using the Wide-field Infrared Survey Explorer (WISE) satellite in January 2010. * : Discovered by the Pan-STARRS survey in December 2020 and later recognised as an Earth trojan in January 2021. It is 1.2 km in diameter. (trailing) * No known objects are currently thought to be trojans of Earth. Searches An Earth-based search for objects was conducted in 1994, covering 0.35 square degrees of sky, under poor observing conditions. Received 24 November 1997; revised 13 April 1998. That search fa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
10 Hygiea
10 Hygiea is a large asteroid located in the outer main asteroid belt between the orbits of Mars and Jupiter. It was the tenth known asteroid, discovered on 12 April 1849 by Italian astronomer Annibale de Gasparis at the Astronomical Observatory of Capodimonte in Naples, Italy. It was named after Hygieia, the Greek goddess of health. It is the fourth-largest main-belt asteroid by both volume and mass, with a mean diameter of and a mass constituting 3% of the main asteroid belt's total mass. Hygiea has a nearly spherical shape, with two known craters about in diameter. Because of its shape and large size, some researchers consider Hygiea a possible dwarf planet. Hygiea has a dark, carbonaceous surface consisting of hydrated and ammoniated silicate minerals, with carbonates and water ice. Hygiea's subsurface likely contains a large fraction of water ice. These characteristics make Hygiea very similar to the main-belt dwarf planet Ceres, which suggests the two objec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
4 Vesta
Vesta (minor-planet designation: 4 Vesta) is one of the largest objects in the asteroid belt, with a mean diameter of . It was discovered by the German astronomer Heinrich Wilhelm Matthias Olbers on 29 March 1807 and is named after Vesta (mythology), Vesta, the virgin goddess of home and hearth from Roman mythology. Vesta is thought to be the second-largest asteroid, both by mass and by volume, after the dwarf planet Ceres (dwarf planet), Ceres. Measurements give it a nominal volume only slightly larger than that of 2 Pallas, Pallas (about 5% greater), but it is 25% to 30% more massive. It constitutes an estimated 9% of the mass of the asteroid belt. Vesta is the only known remaining rocky protoplanet of the kind that formed the terrestrial planets. Numerous fragments of Vesta were ejected by collisions one and two billion years ago that left two enormous craters occupying much of Vesta's southern hemisphere. Debris from these events has fallen to Earth as HED meteorite, howardi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2 Pallas
Pallas (minor-planet designation: 2 Pallas) is the List of largest asteroids, third-largest asteroid in the Solar System by volume and mass. It is the second asteroid to have been discovered, after 1 Ceres, Ceres, and is likely a remnant protoplanet. Like Ceres, it is believed to have a mineral composition similar to carbonaceous chondrite meteorites, though significantly less hydrated than Ceres. It is 79% the mass of 4 Vesta, Vesta and 22% the mass of Ceres, constituting an estimated 7% of the total mass of the asteroid belt. Its estimated volume is equivalent to a sphere in diameter, 90–95% the volume of Vesta. During the planetary formation era of the Solar System, objects grew in size through an accretion (astrophysics), accretion process to approximately the size of Pallas. Most of these protoplanets were incorporated into the growth of larger bodies, which became the planets, whereas others were ejected by the planets or destroyed in collisions with each other. P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dwarf Planet
A dwarf planet is a small planetary-mass object that is in direct orbit around the Sun, massive enough to be hydrostatic equilibrium, gravitationally rounded, but insufficient to achieve clearing the neighbourhood, orbital dominance like the eight classical planets of the Solar System. The prototypical dwarf planet is Pluto, which for decades was regarded as a planet before the "dwarf" concept was adopted in 2006. Dwarf planets are capable of being geologically active, an expectation that was borne out in 2015 by the ''Dawn (spacecraft), Dawn'' mission to and the ''New Horizons'' mission to Pluto. planetary geology, Planetary geologists are therefore particularly interested in them. Astronomers are in general agreement that at least the List of possible dwarf planets#Likeliest dwarf planets, nine largest candidates are dwarf planets – in rough order of diameter, , , , , , , , , and . A considerable uncertainty remains over the tenth largest candidate , which may thus be co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceres (dwarf Planet)
Ceres (minor-planet designation: 1 Ceres) is a dwarf planet in the middle main asteroid belt between the orbits of Mars and Jupiter. It was the first known asteroid, discovered on 1 January 1801 by Giuseppe Piazzi at Palermo Astronomical Observatory in Sicily, and announced as a new planet. Ceres was later classified as an asteroid and then a dwarf planet, the only one not beyond Neptune's orbit. Ceres's diameter is about a quarter that of the Moon. Its small size means that even at its brightest it is too dim to be seen by the naked eye, except under extremely dark skies. Its apparent magnitude ranges from 6.7 to 9.3, peaking at opposition (planets), opposition (when it is closest to Earth) once every 15- to 16-month synodic period. As a result, its surface features are barely visible even with the most powerful telescopes, and little was known about it until the robotic NASA spacecraft Dawn (spacecraft), ''Dawn'' approached Ceres for its orbital mission in 2015. ''Dawn'' fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asteroid Belt
The asteroid belt is a torus-shaped region in the Solar System, centered on the Sun and roughly spanning the space between the orbits of the planets Jupiter and Mars. It contains a great many solid, irregularly shaped bodies called asteroids or minor planets. The identified objects are of many sizes, but much smaller than planets, and, on average, are about one million kilometers (or six hundred thousand miles) apart. This asteroid belt is also called the main asteroid belt or main belt to distinguish it from other asteroid populations in the Solar System. The asteroid belt is the smallest and innermost circumstellar disc in the Solar System. Classes of Small Solar System body, small Solar System bodies in other regions are the near-Earth objects, the Centaur (minor planet), centaurs, the Kuiper belt objects, the scattered disc objects, the sednoids, and the Oort cloud objects. About 60% of the main belt mass is contained in the four largest asteroids: Ceres (dwarf planet), C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asteroid
An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). Asteroids are rocky, metallic, or icy bodies with no atmosphere, and are broadly classified into C-type asteroid, C-type (carbonaceous), M-type asteroid, M-type (metallic), or S-type asteroid, S-type (silicaceous). The size and shape of asteroids vary significantly, ranging from small rubble piles under a kilometer across to Ceres (dwarf planet), Ceres, a dwarf planet almost 1000 km in diameter. A body is classified as a comet, not an asteroid, if it shows a coma (tail) when warmed by solar radiation, although recent observations suggest a continuum between these types of bodies. Of the roughly one million known asteroids, the greatest number are located between the orbits of Mars and Jupiter, approximately 2 to 4 astronomical unit, AU ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Mars-crossing Minor Planets
A Mars-crossing asteroid (MCA, also Mars-crosser, MC) is an asteroid whose orbit crosses that of Mars. Some Mars-crossers numbered below 100000 are listed here. They include the two numbered Mars trojans 5261 Eureka and . Many databases, for instance the JPL Small-Body Database (JPL SBDB), only list asteroids with a perihelion greater than 1.3 AU as Mars-crossers. An asteroid with a perihelion less than this is classed as a near-Earth object even though it is crossing the orbit of Mars as well as crossing (or coming near to) that of Earth. Nevertheless, these objects are listed on this page. A grazer is an object with a perihelion below the aphelion of Mars (1.67 AU) but above the Martian perihelion (1.38 AU). The JPL SBDB lists 13,500 Mars-crossing asteroids. Only 18 MCAs are brighter than absolute magnitude (H) 12.5, which typically makes these asteroids with H<12.5 more than 13 km in diameter depending on the |
Mars Trojan
The Mars trojans are a group of trojan objects that share the orbit of the planet Mars around the Sun. They can be found around the two Lagrangian points 60° ahead of and behind Mars. The origin of the Mars trojans is not well understood. One theory suggests that they were primordial objects left over from the formation of Mars that were captured in its Lagrangian points as the Solar System was forming. However, spectral studies of the Mars trojans indicate this may not be the case. Another explanation involves asteroids chaotically wandering into the Mars Lagrangian points later in the Solar System's formation. This is also questionable considering the short dynamical lifetimes of these objects. The spectra of Eureka and two other Mars trojans indicates an olivine-rich composition. Since olivine-rich objects are rare in the asteroid belt it has been suggested that some of the Mars trojans are captured debris from a large orbit-altering impact on Mars when it encountered a planet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phobos (moon)
Phobos (; astronomical naming conventions, systematic designation: ) is the innermost and larger of the two moons of Mars, natural satellites of Mars, the other being Deimos (moon), Deimos. The two moons were discovered in 1877 by American astronomer Asaph Hall. Phobos is named after Phobos (mythology), the Greek god of fear and panic, who is the son of Ares (Mars) and twin brother of Deimos (deity), Deimos. Phobos is a small, irregularly shaped object with a mean radius of . It orbits from the Martian surface, closer to its Primary (astronomy), primary body than any other known natural satellite to a planet. It orbits Mars much faster than Mars rotates and completes an orbit in just 7 hours and 39 minutes. As a result, from the surface of Mars it appears to rise in the west, move across the sky in 4 hours and 15 minutes or less, and set in the east, twice each Mars sol, Martian day. Phobos is one of the least reflective bodies in the Solar System, with an albedo of 0.071. Su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
