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Encyclopedia > Asteroid
253 Mathilde, a C-type asteroid measuring about 50 km across. Photograph taken in 1997 by the NEAR Shoemaker probe.
253 Mathilde, a C-type asteroid measuring about 50 km across. Photograph taken in 1997 by the NEAR Shoemaker probe.

Asteroids, also called minor planets or planetoids, are Solar System bodies smaller than planets but larger than meteoroids (which are commonly defined as being 10 meters across or less),[1] and that are not comets. The distinction between asteroids and comets is made on visual appearance when discovered: comets must show a perceptible coma (a fuzzy "atmosphere"), while asteroids do not. Image File history File links Merge-arrows. ... Minor planets, or asteroids or planetoids, are minor celestial bodies of the Solar system orbiting the Sun (mostly Small solar system bodies) that are smaller than major planets, but larger than meteoroids (commonly defined as being 10 meters across or less[1]), and that are not comets. ... Asteroid (plural form: Asteroids) may refer to: Asteroid, the astronomical object; this is the primary definition. ... Image File history File links (253)_mathilde. ... Image File history File links (253)_mathilde. ... 253 Mathilde is a Main belt asteroid that was visited by the NEAR Shoemaker spacecraft on its way to asteroid 433 Eros. ... C-type asteroids are carbonaceous asteroids. ... Artists conception of the NEAR Shoemaker spacecraft Near Earth Asteroid Eros as seen from the NEAR spacecraft. ... Minor planet is the official term for asteroids and trans-Neptunian objects. ... This article is about the Solar System. ... Meteor redirects here. ... Comet Hale-Bopp Comet West For other uses, see Comet (disambiguation). ... The comet Ikeya-Zhang exhibiting a bright, condensed coma (march 2002) In astronomy, the nebulous envelope around the nucleus of a comet is called its coma (from the Latin word for hair). It is formed when the comet passes close to the sun on its highly elliptical orbit; as the...


An ateroid is a chunck of rock and ice that is too small and numeroud to be considered a planet. Asteroids must be within the orbit of the sun and be between Mars and Jupiter. If it leaves its orbit it is considered a meteor, meteoroid, or a meteorite. Asteroids vary greatly in size, from a few hundreds of kilometres in diameter down to rocks just tens of metres across. A few of the largest are roughly spherical and are very much like miniature planets. The vast majority, however, are much smaller and are irregularly shaped. The physical composition of asteroids is varied and in many cases poorly understood. Some are solid rocky bodies, with a greater or lesser metallic content, while others are piles of rubble held together loosely by gravity. Only one asteroid—Vesta—is visible to the naked eye, and this only in very dark skies when it is favourably positioned. 4 Vesta (ves-ta) is the second most massive asteroid in the asteroid belt, with a mean diameter of about 530 km and an estimated mass 12% the mass of the entire asteroid belt. ...


The first named minor planet, Ceres, was discovered in 1801 by Giuseppe Piazzi, and was originally considered a new planet.[2] This was followed by the discovery of other similar bodies, which with the equipment of the time appeared to be points of light, like stars, showing little or no planetary disc (though readily distinguishable from stars due to their apparent motions). This prompted the astronomer Sir William Herschel to propose the term "asteroid", from Greek αστεροειδής, asteroeidēs = star-like, star-shaped, from ancient Greek Aστήρ, astēr = star. Spectral type: G[8] Absolute magnitude: 3. ... Giuseppe Piazzi. ... For other persons named William Herschel, see William Herschel (disambiguation). ...


The vast majority of known asteroids are found within the main asteroid belt, between the orbits of Mars and Jupiter, generally in relatively low-eccentricity (i.e., not very elongated) orbits. This belt is estimated to contain more than 750,000 asteroids larger than 1 kilometer across, and millions of smaller ones.[3] It is thought that these asteroids are remnants of the protoplanetary disk, and in this region the accretion of planetesimals into planets during the formative period of the solar system was prevented by large gravitational perturbations by Jupiter. Some asteroids have moons or are found in co-orbiting pairs known as binary systems. Minor planets have more recently been found to cross the orbits of planets, from Mercury to Neptune—with hundreds of trans-Neptunian objects (TNOs) now known to exist well past Neptune's orbit. (Using indirect methods, the total number of TNOs has been estimated in the hundreds of millions or even billions.) For other uses, see Asteroid (disambiguation). ... This article is about the planet. ... For other uses, see Jupiter (disambiguation). ... (This page refers to eccitricity in astrodynamics. ... A protoplanetary disc (also protoplanetary disk, proplyd) is an accretion disc surrounding a T Tauri star. ... In astrophysics, the term accretion is used for at least two distinct processes. ... Planetesimals are solid objects thought to exist in protoplanetary disks and in debris disks. ... For other uses, see Jupiter (disambiguation). ... 243 Ida and its moon Dactyl An asteroid moon is an asteroid that orbits another asteroid. ... The term binary asteroid refers to a system in which two asteroids orbit their common centre of gravity, in analogy with binary stars. ... This article is about the planet. ... For other uses, see Neptune (disambiguation). ... A trans-Neptunian object (TNO) is any object in the solar system that orbits the sun at a greater distance on average than Neptune. ...


Asteroids are given a provisional designation by year in the order of discovery, and a designation (a sequential number) and name if their existence is well established and an orbit has been determined. Two bodies with a slight difference in mass orbiting around a common barycenter. ...

Contents

Terminology

The term "asteroid" is used to describe any of a diverse group of small celestial bodies orbiting the Sun—traditionally in the inner Solar System, since those were the only ones known. In English it is the most commonly used word for a minor planet,[citation needed] which was the term preferred by the International Astronomical Union (IAU) prior to 2006. Other languages prefer "planetoid" (Greek for "planet-like"). The word "planetesimal" has a similar meaning, but often refers specifically to small bodies that existed at the time the Solar System was forming. The term "planetule" was coined by the geologist Conybeare to describe minor planets,[4] but is not in common use. Minor planets, or asteroids or planetoids, are minor celestial bodies of the Solar system orbiting the Sun (mostly Small solar system bodies) that are smaller than major planets, but larger than meteoroids (commonly defined as being 10 meters across or less[1]), and that are not comets. ... IAU redirects here. ... Planetesimals are solid objects thought to exist in protoplanetary disks and in debris disks. ...


Traditionally, small bodies orbiting the Sun were classified as asteroids, comets or meteoroids, with anything smaller than, say, ten metres across being called a meteoroid. The main difference between an asteroid and a comet is that a comet shows a coma due to sublimation of near surface ices by solar radiation. A few objects have ended up being dual-listed because they were first classified as minor planets but later showed evidence of cometary activity. Conversely, some (perhaps all) comets eventually are depleted of their volatile ices and then appear as point-like objects, i.e. asteroids. A further distinction is that comets typically have more eccentric orbits than asteroids (though some objects classified as asteroids also have notably eccentric orbits). Comet Hale-Bopp, showing a white dust tail and blue gas tail (February 1997) A comet is a small astronomical object similar to an asteroid but composed largely of ice. ... Worlds second largest Meteorite in Culiacan, Mexico A meteorite is a relatively small extra-terrestrial body that reaches the Earths surface. ... Outgassing (sometimes called Offgassing, particularly when in reference to indoor air quality) is the slow release of a gas that was trapped, frozen, absorbed or adsorbed in some material. ...


In recent years, the situation has been complicated by the discovery of trans-Neptunian objects (TNOs). These inhabit the cold outer reaches of the Solar System where ices remain solid and comet-like bodies are not expected to exhibit much cometary activity. The innermost of these are the Kuiper Belt Objects (KBOs), called "objects" partly to avoid the need to classify them as asteroids or comets.[5] KBOs are believed to be predominantly comet-like in composition, though some may be more akin to asteroids.[6] Furthermore, they do not necessarily have the highly eccentric orbits usually associated with comets, and there are significant numbers very much larger than traditional comet nuclei. The much more distant Oort cloud is also hypothesised to be a reservoir of dormant comets. A trans-Neptunian object (TNO) is any object in the solar system that orbits the sun at a greater distance on average than Neptune. ... Artists rendering of the Kuiper Belt and hypothetical more distant Oort cloud. ... The solid, central part of a comet is known as the comet nucleus. ... Artists rendering of the Oort cloud and the Kuiper Belt. ...


Other recent observations, such as the analysis of the cometary dust collected by the Stardust probe, are increasingly blurring the distinction between comets and asteroids,[7] suggesting "a continuum between asteroids and comets" rather than a sharp dividing line.[8] An artists rendering of Stardust (NASA image) The Stardust capsule with cometary and interstellar samples landed at the U.S. Air Force Utah Test and Training Range at 10:10 UTC (15 January 2006) in the Bonneville Salt Flats. ...


In late August 2006, the IAU introduced the class small solar system bodies (SSSB) to include most objects previously classified as minor planets and comets. At the same time, the class dwarf planets was created for the largest minor planets—those which have sufficient mass to have become more-or-less spherical under their own gravity. According to the IAU, "the term 'minor planet' may still be used, but generally the term 'small solar system body' will be preferred."[9] Currently only the largest object in the asteroid belt, Ceres, at about 950 km across, is in the dwarf planet category, although there are several relatively large near-spherical asteroids (Vesta, Pallas and Hygiea) that may be reclassified as dwarf planets in future.[10] The final definition left the solar system with eight planets. ... A Small Solar System Body (SSSB) is a term defined in 2006 by the International Astronomical Union to describe objects in the Solar System that are neither planets nor dwarf planets: [1] This encompasses: all minor planets apart from the dwarf planets, : the classical asteroids, (except for 1 Ceres, the... Comet Hale-Bopp, showing a white dust tail and blue gas tail (February 1997) A comet is a small astronomical object similar to an asteroid but composed largely of ice. ... Artists impression of Pluto (background) and Charon (foreground). ... Spectral type: G[8] Absolute magnitude: 3. ... 4 Vesta (ves-ta) is the second most massive asteroid in the asteroid belt, with a mean diameter of about 530 km and an estimated mass 12% the mass of the entire asteroid belt. ... 2 Pallas (pal-us, Greek Παλλάς) was the first asteroid discovered after 1 Ceres. ... 10 Hygiea (hye-jee-a or hi-jee-a) is the fourth largest Main belt asteroid with a diameter of 407 km. ...


Distribution within the Solar System

See also: Asteroid group, List of noteworthy asteroids, and List of asteroids
The Main asteroid belt (white) and the Trojan asteroids (green)
The Main asteroid belt (white) and the Trojan asteroids (green)

Hundreds of thousands of asteroids have been discovered within the Solar System, with the rate of discovery currently running at around 5,000 per month. Of the more than 400,000 registered minor planets, 189,005 have orbits known well enough to be assigned permanent official numbers.[11][12] Of these, 14,574 have official names.[13] The lowest-numbered, unnamed minor planet is (3708) 1974 FV1;[14] the highest-numbered named minor planet is 184878 Gotlib.[15] Current estimates put the total number of asteroids above 1 km in diameter in the Solar System to be between 1.1 and 1.9 million.[16] Ceres, with diameters of 975 × 909 km, was once considered the largest asteroid in the inner solar system, but it has since been recategorized as a dwarf planet. That distinction now falls to 2 Pallas and 4 Vesta; both have diameters of about 500 km. Normally Vesta is the only main belt asteroid that can, on occasion, become visible to the naked eye. However, on some very rare occasions, a near-Earth asteroid may briefly become visible without technical aid; see 99942 Apophis. Minor planet is the official term for asteroids and trans-Neptunian objects. ... The following is a collection of lists of noteworthy asteroids in the Solar system, sometimes also including minor planets beyond the orbit of Jupiter. ... This is a list of numbered minor planets, nearly all of them asteroids, in sequential order. ... Image File history File links Download high-resolution version (768x768, 188 KB)The inner Solar System, from the Sun to Jupiter. ... Image File history File links Download high-resolution version (768x768, 188 KB)The inner Solar System, from the Sun to Jupiter. ... For other uses, see Asteroid (disambiguation). ... As originally defined, Trojan asteroids have a semi-major axis between 5. ... In ancient times, only the Sun and Moon, a few hundred stars and the most easily visible planets had names. ... Spectral type: G[8] Absolute magnitude: 3. ... Artists impression of Pluto (background) and Charon (foreground). ... 2 Pallas (pal-us, Greek Παλλάς) was the first asteroid discovered after 1 Ceres. ... 4 Vesta (ves-ta) is the second most massive asteroid in the asteroid belt, with a mean diameter of about 530 km and an estimated mass 12% the mass of the entire asteroid belt. ... Close approach of Apophis on April 13, 2029 The white bar indicates uncertainty in the range of positions 99942 Apophis 99942 Apophis (pronounced , previously known by its provisional designation ) is a near-Earth asteroid that caused a brief period of concern in December 2004 because initial observations indicated a relatively...

Left to right: 4 Vesta, 1 Ceres, Earth's Moon
Left to right: 4 Vesta, 1 Ceres, Earth's Moon

The mass of all the objects of the Main asteroid belt, lying between the orbits of Mars and Jupiter, is estimated to be about 3.0-3.6×1021 kg, or about 4 percent of the mass of the Moon. Of this, Ceres comprises 0.95×1021 kg, some 32 percent of the total.[17][18] Adding in the next three most massive asteroids, 4 Vesta (9%), 2 Pallas (7%), and 10 Hygiea (3%), brings this figure up to 51%; while the three after that, 511 Davida (1.2%), 704 Interamnia (1.0%), and 52 Europa (0.9%), only add another 3% to the total mass. The number of asteroids then increases rapidly as their individual masses decrease. Image File history File links The asteroids 4 Vesta and 1 Ceres shown alongside the Earths Moon. ... Image File history File links The asteroids 4 Vesta and 1 Ceres shown alongside the Earths Moon. ... 4 Vesta (ves-ta) is the second most massive asteroid in the asteroid belt, with a mean diameter of about 530 km and an estimated mass 12% the mass of the entire asteroid belt. ... Spectral type: G[8] Absolute magnitude: 3. ... This article is about Earths moon. ... For other uses, see Asteroid (disambiguation). ... This article is about the planet. ... For other uses, see Jupiter (disambiguation). ... This article is about Earths moon. ... Spectral type: G[8] Absolute magnitude: 3. ... 4 Vesta (ves-ta) is the second most massive asteroid in the asteroid belt, with a mean diameter of about 530 km and an estimated mass 12% the mass of the entire asteroid belt. ... 2 Pallas (pal-us, Greek Παλλάς) was the first asteroid discovered after 1 Ceres. ... 10 Hygiea (hye-jee-a or hi-jee-a) is the fourth largest Main belt asteroid with a diameter of 407 km. ... 511 Davida is a main belt asteroid. ... 704 Interamnia (IN ter AM nia) is a very large asteroid with a diameter of 350 kilometres. ... 52 Europa, diameter 289 km, was discovered on February 4, 1858 by H. Goldschmidt. ...


Various classes of asteroid have been discovered outside the main asteroid belt. Near-Earth asteroids have orbits in the vicinity of Earth's orbit. Trojan asteroids are gravitationally locked into synchronisation with a planet, either leading or trailing the planet in its orbit. The majority of Trojans are associated with Jupiter, but a few have been found orbiting with Mars or Neptune. Asteroids orbiting between Jupiter and Neptune are called Centaurs, and beyond this lie swarms of trans-Neptunian objects. A group of asteroids called Vulcanoids are hypothesised by some to lie very close to the Sun, within the orbit of Mercury, but none has so far been found. Near-Earth asteroids (NEAs) are asteroids whose orbits are close to Earths orbit. ... As originally defined, Trojan asteroids have a semi-major axis between 5. ... For other uses, see Jupiter (disambiguation). ... This article is about the planet. ... For other uses, see Neptune (disambiguation). ... For other uses, see Jupiter (disambiguation). ... For other uses, see Neptune (disambiguation). ... The centaurs are a class of icy planetoids that orbit the Sun between Jupiter and Neptune, named after the mythical race of centaurs. ... A trans-Neptunian object (TNO) is any object in the solar system with all or most of its orbit beyond that of Neptune. ... Vulcanoids are hypothetical asteroids that may orbit in a dynamically stable zone between 0. ... This article is about the planet. ...


Classification

Asteroids are commonly classified according to two criteria: the characteristics of their orbits, and features of their reflectance spectrum. Visible light redirects here. ...


Orbit groups and families

Main articles: Asteroid group and Asteroid family

Many asteroids have been placed in groups and families based on their orbital characteristics. Apart from the broadest divisions, it is customary to name a group of asteroids after the first member of that group to be discovered. Groups are relatively loose dynamical associations, whereas families are much tighter and result from the catastrophic break-up of a large parent asteroid sometime in the past.[19] Families have only been recognized within the main asteroid belt. They were first recognised by Kiyotsugu Hirayama in 1918 and are often called Hirayama families in his honor. Minor planet is the official term for asteroids and trans-Neptunian objects. ... Minor planet is the official term for asteroids and trans-Neptunian objects. ... The asteroid belt is a region of the solar system falling roughly between the planets Mars and Jupiter where the greatest concentration of asteroid orbits can be found. ... Kiyotsugu Hirayama (平山清次) (1874–1943) was a Japanese astronomer, best known for his discovery that many asteroid orbits were more similar to one another than chance would allow, leading to the concept of asteroid families, now called Hirayama families in his honour. ... A Hirayama family of asteroids is a group of minor planets that share similar orbital elements, such as semimajor axis, eccentricity, and orbital inclination. ...


About 30% to 35% of the bodies in the main belt belong to dynamical families each thought to have a common origin in a past collision between asteroids. A family has also been associated with the Trans-Neptunian Object (136108) 2003 EL61. (also written (136108) 2003 EL61), nicknamed Easter Bunny, is a large Kuiper belt object, roughly one-third the mass of Pluto, discovered by J. L. Ortiz et al. ...


Quasi-satellites and horseshoe objects

Some asteroids have unusual horseshoe orbits that are co-orbital with the Earth or some other planet. Examples are 3753 Cruithne and 2002 AA29. The first instance of this type of orbital arrangement was discovered between Saturn's moons Epimetheus and Janus. A horseshoe orbit is the type of orbit you get when you observe an object from another nearly co-orbital object, such as a planet. ... This article is about Earth as a planet. ... 3753 Cruithne (pronounced , Modern Irish ) is an asteroid in orbit around the Sun. ... Asteroid 2002 AA29 (also written 2002 AA29) is a near-Earth asteroid discovered in January 2001 by the LINEAR asteroid survey. ... This article is about the planet. ... Epimetheus (ep-i-mee-thee-us, Greek Επιμηθεύς) is a moon of Saturn. ... Janus (jay-nus, IPA: , Greek Ιανός) is an inner satellite of Saturn. ...


Sometimes these horseshoe objects temporarily become quasi-satellites for a few decades or a few hundred years, before returning to their prior status. Both Earth and Venus are known to have quasi-satellites. Diagram of generic quasi-satellite orbit A quasi-satellite is an object similar to a planet or satellite of the Sun, however its orbit encompasses its planet and the planets star. ... This article is about the planet. ...


Such objects, if associated with Earth or Venus or even hypothetically Mercury are a special class of Aten asteroids. However, such objects could be associated with outer planets as well. This article is about the planet. ... The Aten asteroids are a group of near-Earth asteroids, named after the first of the group to be discovered (2062 Aten, discovered January 7, 1976 by Eleanor F. Helin). ...


Spectral classification

This picture of 433 Eros shows the view looking from one end of the asteroid across the gouge on its underside and toward the opposite end. Features as small as 35 m across can be seen.
This picture of 433 Eros shows the view looking from one end of the asteroid across the gouge on its underside and toward the opposite end. Features as small as 35 m across can be seen.

In 1975, an asteroid taxonomic system based on colour, albedo, and spectral shape was developed by Clark R. Chapman, David Morrison, and Ben Zellner.[20] These properties are thought to correspond to the composition of the asteroid's surface material. The original classification system had three categories: C-types for dark carbonaceous objects (75% of known asteroids), S-types for stony (silicaceous) objects (17% of known asteroids) and U for those that did not fit into either C or S. This classification has since been expanded to include a number of other asteroid types. The number of types continues to grow as more asteroids are studied. Image File history File links Download high-resolution version (1024x691, 68 KB) Other versions [4] File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Asteroid 433 Eros Wikipedia talk:WikiProject Astronomical objects/Archive 1 Wikipedia:Selected anniversaries/February Wikipedia... Image File history File links Download high-resolution version (1024x691, 68 KB) Other versions [4] File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Asteroid 433 Eros Wikipedia talk:WikiProject Astronomical objects/Archive 1 Wikipedia:Selected anniversaries/February Wikipedia... The asteroid 433 Eros (eer-os) was named after the Greek god of love Eros. ... Asteroids are assigned a type based on spectral shape, color, and sometimes albedo. ... For the science of classifying living things, see alpha taxonomy. ... Color is an important part of the visual arts. ... For other uses, see Albedo (disambiguation). ... A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from an excess or deficiency of photons in a narrow frequency range, compared with the nearby frequencies. ... C-type asteroids are carbonaceous asteroids. ... S-type asteroids are of a silicaceous (stony) composition, hence the name. ...


The two most widely used taxonomies currently used are the Tholen classification and SMASS classification. The former was proposed in 1984 by David J. Tholen, and was based on data collected from an eight-color asteroid survey performed in the 1980s. This resulted in 14 asteroid categories.[21] In 2002, the Small Main-Belt Asteroid Spectroscopic Survey resulted in a modified version of the Tholen taxonomy with 24 different types. Both systems have three broad categories of C, S, and X asteroids, where X consists of mostly metallic asteroids, such as the M-type. There are also a number of smaller classes.[22] David J. Tholen is an American astronomer at the Institute for Astronomy of the University of Hawaii, who specializes in planetary and solar system astronomy. ... M-type asteroids are metallic asteroids; they are moderately bright (albedo . ...


Note that the proportion of known asteroids falling into the various spectral types does not necessarily reflect the proportion of all asteroids that are of that type; some types are easier to detect than others, biasing the totals.


Problems with spectral classification

Originally, spectral designations were based on inferences of an asteroid's composition.[23] However, the correspondence between spectral class and composition is not always very good, and there are a variety of classifications in use. This has led to significant confusion. While asteroids of different spectral classifications are likely to be composed of different materials, there are no assurances that asteroids within the same taxonomic class are composed of similar materials.


At present, the spectral classification based on several coarse resolution spectroscopic surveys in the 1990s is still the standard. Scientists have been unable to agree on a better taxonomic system[citation needed], largely due to the difficulty of obtaining detailed measurements consistently for a large sample of asteroids (e.g. finer resolution spectra, or non-spectral data such as densities would be very useful).


Discovery

243 Ida and its moon Dactyl, the first satellite of an asteroid to be discovered.
243 Ida and its moon Dactyl, the first satellite of an asteroid to be discovered.

NASA image of 243 Ida and Dactyl. ... NASA image of 243 Ida and Dactyl. ... NASA image of 243 Ida. ...

Historical methods

Asteroid discovery methods have dramatically improved over the past two centuries.


In the last years of the 18th century, Baron Franz Xaver von Zach organized a group of 24 astronomers to search the sky for the missing planet predicted at about 2.8 AU from the Sun by the Titius-Bode law, partly as a consequence of the discovery, by Sir William Herschel in 1781, of the planet Uranus at the distance predicted by the law. This task required that hand-drawn sky charts be prepared for all stars in the zodiacal band down to an agreed-upon limit of faintness. On subsequent nights, the sky would be charted again and any moving object would, hopefully, be spotted. The expected motion of the missing planet was about 30 seconds of arc per hour, readily discernible by observers. Franz Xaver, Baron Von Zach Baron Franz Xaver von Zach (Franz Xaver Freiherr von Zach) (June 4, 1754 - September 2, 1832) was an Austrian astronomer born at Bratislava. ... The astronomical unit (AU or au or a. ... Sol redirects here. ... The Titius-Bode law (or Bodes law) is the observation that orbits of planets in the solar system closely follow a simple geometric rule. ... For other persons named William Herschel, see William Herschel (disambiguation). ... For other uses, see Uranus (disambiguation). ... For other uses, see Zodiac (disambiguation). ...


Ironically, the first asteroid, 1 Ceres, was not discovered by a member of the group, but rather by accident in 1801 by Giuseppe Piazzi, director of the observatory of Palermo in Sicily. He discovered a new star-like object in Taurus and followed the displacement of this object during several nights. His colleague, Carl Friedrich Gauss, used these observations to determine the exact distance from this unknown object to the Earth. Gauss' calculations placed the object between the planets Mars and Jupiter. Piazzi named it after Ceres, the Roman goddess of agriculture. Spectral type: G[8] Absolute magnitude: 3. ... Giuseppe Piazzi. ... Location of the city of Palermo (red dot) within Italy. ... Sicily ( in Italian and Sicilian) is an autonomous region of Italy and the largest island in the Mediterranean Sea, with an area of 25,708 km² (9,926 sq. ... Taurus (IPA: , Latin: , symbol , ) is one of the constellations of the zodiac. ... Johann Carl Friedrich Gauss (pronounced ,  ; in German usually Gauß, Latin: ) (30 April 1777 – 23 February 1855) was a German mathematician and scientist who contributed significantly to many fields, including number theory, statistics, analysis, differential geometry, geodesy, electrostatics, astronomy, and optics. ... This article is about the planet. ... For other uses, see Jupiter (disambiguation). ... In Roman mythology, Ceres was the goddess of growing plants (particularly cereals) and of motherly love. ...


Three other asteroids (2 Pallas, 3 Juno, and 4 Vesta) were discovered over the next few years, with Vesta found in 1807. After eight more years of fruitless searches, most astronomers assumed that there were no more and abandoned any further searches. 2 Pallas (pal-us, Greek Παλλάς) was the first asteroid discovered after 1 Ceres. ... Juno (IPA: ), designated 3 Juno in the Minor Planet Center catalogue system, was the third asteroid to be discovered and is one of the largest main belt asteroids, being the second heaviest of the stony S-type. ... 4 Vesta (ves-ta) is the second most massive asteroid in the asteroid belt, with a mean diameter of about 530 km and an estimated mass 12% the mass of the entire asteroid belt. ...


However, Karl Ludwig Hencke persisted, and began searching for more asteroids in 1830. Fifteen years later, he found 5 Astraea, the first new asteroid in 38 years. He also found 6 Hebe less than two years later. After this, other astronomers joined in the search and at least one new asteroid was discovered every year after that (except the wartime year 1945). Notable asteroid hunters of this early era were J. R. Hind, Annibale de Gasparis, Robert Luther, H. M. S. Goldschmidt, Jean Chacornac, James Ferguson, Norman Robert Pogson, E. W. Tempel, J. C. Watson, C. H. F. Peters, A. Borrelly, J. Palisa, the Henry brothers and Auguste Charlois. Karl Ludwig Hencke (April 8, 1793 – September 25, 1866) was a German astronomer. ... 5 Astraea (as-tree-a; written Astræa in the early scientific litterature) is a large main belt asteroid. ... 6 Hebe (hee-bee, Greek ‘Ήβη) is a very large Main belt asteroid. ... John Russell Hind (May 12, 1823 – December 23, 1895) was a British astronomer. ... Annibale de Gasparis (April 9, 1819 – March 21, 1892) was an Italian astronomer. ... Karl Theodor Robert Luther (April 16, 1822 – February 15, 1900) was a German astronomer who searched for asteroids while working in Düsseldorf. ... Hermann Mayer Salomon Goldschmidt (June 17, 1802 – April 26, 1866) was a German astronomer and painter who spent much of his life in France. ... Jean Chacornac (June 21, 1823 – September 23, 1873) was a French astronomer. ... James Ferguson (August 31, 1797 - September 26, 1867) was an American astronomer born in Scotland who made the first discovery of an asteroid in North America. ... Norman Robert Pogson (March 23, 1829 – June 23, 1891) was a British astronomer. ... Ernst Wilhelm Leberecht Tempel (December 4, 1821 – March 16, 1889) was a German astronomer who worked in Marseille until the outbreak of the Franco-Prussian War in 1870, then later moved to Italy. ... James Craig Watson (January 28, 1838 – November 22, 1880) was a Canadian-American astronomer born in the village of Fingal in Ontario, Canada. ... Christian Heinrich Friedrich Peters (September 19, 1813 – July 18, 1890) was an American astronomer, and one of the first to discover asteroids. ... Alphonse Louis Nicolas Borrelly (December 8, 1842 – February 28, 1926) was a French astronomer. ... Johann Palisa (December 6, 1848 – May 2, 1925) was an Austrian astronomer, born in Troppau in Austrian Silesia (now in the Czech Republic). ... Paul-Pierre Henry (Paul Henry) (August 21, 1848 – January 4, 1905) and his brother Mathieu-Prosper Henry (Prosper Henry) (December 10, 1849 – July 25, 1903) were French opticians and astronomers. ... Auguste Honoré Charlois (November 26, 1864 – March 26, 1910) was a French astronomer who discovered 99 asteroids while working in Nice. ...


In 1891, however, Max Wolf pioneered the use of astrophotography to detect asteroids, which appeared as short streaks on long-exposure photographic plates. This dramatically increased the rate of detection compared with previous visual methods: Wolf alone discovered 248 asteroids, beginning with 323 Brucia, whereas only slightly more than 300 had been discovered up to that point. Still, a century later, only a few thousand asteroids were identified, numbered and named. It was known that there were many more, but most astronomers did not bother with them, calling them "vermin of the skies". Maximilian Franz Joseph Cornelius Wolf (June 21, 1863 – October 3, 1932) was a German astronomer. ... Astrophotography is a specialised type of photography that entails making photographs of astronomical objects in the night sky such as planets, stars, and deep sky objects such as star clusters and galaxies. ... 323 Brucia was the first asteroid to be discovered by the use of astrophotography. ...


Manual methods of the 1900s and modern reporting

Until 1998, asteroids were discovered by a four-step process. First, a region of the sky was photographed by a wide-field telescope, or Astrograph. Pairs of photographs were taken, typically one hour apart. Multiple pairs could be taken over a series of days. Second, the two films of the same region were viewed under a stereoscope. Any body in orbit around the Sun would move slightly between the pair of films. Under the stereoscope, the image of the body would appear to float slightly above the background of stars. Third, once a moving body was identified, its location would be measured precisely using a digitizing microscope. The location would be measured relative to known star locations.[24] For other uses, see Photograph (disambiguation). ... This article does not cite any references or sources. ... A 13-inch, f/5. ... This article is about motion pictures. ... Pocket stereoskop WILD 1985 Old Zeiss pocket stereoscope with original test image Stereo card of a stereoscope in use. ...


These first three steps do not constitute asteroid discovery: the observer has only found an apparition, which gets a provisional designation, made up of the year of discovery, a letter representing the week of discovery, and finally a letter and a number indicating the discovery's sequential number (example: 1998 FJ74). Provisional designation of in astronomy is the naming convention applied to astronomical objects immediately following their discovery. ...


The final step of discovery is to send the locations and time of observations to the Minor Planet Center, where computer programs determine whether an apparition ties together previous apparitions into a single orbit. If so, the object receives a catalogue number and the observer of the first apparition with a calculated orbit is declared the discoverer, and granted the honor of naming the object subject to the approval of the International Astronomical Union. The Minor Planet Center operates at the Smithsonian Astrophysical Observatory (SAO), which is part of the Center for Astrophysics (CfA) along with the Harvard College Observatory (HCO). ... IAU redirects here. ...


Computerized methods

2004 FH is the center dot being followed by the sequence; the object that flashes by during the clip is an artificial satellite.
2004 FH is the center dot being followed by the sequence; the object that flashes by during the clip is an artificial satellite.

There is increasing interest in identifying asteroids whose orbits cross Earth's, and that could, given enough time, collide with Earth (see Earth-crosser asteroids). The three most important groups of near-Earth asteroids are the Apollos, Amors, and Atens. Various asteroid deflection strategies have been proposed, as early as the 1960s. Timelapse of Asteroid 2004 FHs flyby (NASA/JPL Public Domain) 2004 FH is the centre dot being followed by the sequence; the object that flashes by near the end is a meteor. ... 2004 FH is a near-Earth asteroid that was discovered on March 15, 2004 by the NASA-funded LINEAR asteroid survey. ... This article is about artificial satellites. ... This article is about Earth as a planet. ... Diagram showing different asteroid paths. ... Computer model of the Apollo Asteroid 6489 Golevka Near-Earth asteroids (NEAs) are asteroids whose orbits are close to Earths orbit. ... The Apollo asteroid 25143 Itokawa. ... The Amor asteroids are a group of near-Earth asteroids named after the asteroid 1221 Amor. ... The Aten asteroids are a group of near-Earth asteroids, named after the first of the group to be discovered (2062 Aten, discovered January 7, 1976 by Eleanor F. Helin). ... Artists impression of a major impact event. ...


The near-Earth asteroid 433 Eros had been discovered as long ago as 1898, and the 1930s brought a flurry of similar objects. In order of discovery, these were: 1221 Amor, 1862 Apollo, 2101 Adonis, and finally 69230 Hermes, which approached within 0.005 AU of the Earth in 1937. Astronomers began to realize the possibilities of Earth impact. Near-Earth objects (NEO) are asteroids, comets and large meteoroids whose orbit intersects Earths orbit and which may therefore pose a collision danger. ... The asteroid 433 Eros (eer-os) was named after the Greek god of love Eros. ... 1221 Amor is the namesake of the Amor asteroids, a group of near-Earth asteroids whose orbits range between those of Earth and Mars. ... 1862 Apollo is a Q-type asteroid, discovered by Karl Reinmuth in 1932, but lost and not recovered until 1973. ... 2101 Adonis was one of the first near-Earth asteroids to be discovered. ... 69230 Hermes is an Apollo, Mars- and Venus-crosser asteroid that passed within 0. ... The astronomical unit (AU or au or a. ... This article is about Earth as a planet. ...


Two events in later decades increased the level of alarm: the increasing acceptance of Walter Alvarez' hypothesis that an impact event resulted in the Cretaceous-Tertiary extinction, and the 1994 observation of Comet Shoemaker-Levy 9 crashing into Jupiter. The U.S. military also declassified the information that its military satellites, built to detect nuclear explosions, had detected hundreds of upper-atmosphere impacts by objects ranging from one to 10 metres across. Walter Alvarez (born 1940), son of Nobel Prize winning physicist Luis Alvarez, is a professor in the Earth and Planetary Science department at the University of California, Berkeley. ... Artists impression of a major impact event. ... Badlands near Drumheller, Alberta where erosion has exposed the KT boundary. ... Hubble Space Telescope image of Comet Shoemaker-Levy 9, taken on May 17, 1994. ... For other uses, see Jupiter (disambiguation). ...


All of these considerations helped spur the launch of highly efficient automated systems that consist of Charge-Coupled Device (CCD) cameras and computers directly connected to telescopes. Since 1998, a large majority of the asteroids have been discovered by such automated systems. A list of teams using such automated systems includes:[25] A specially developed CCD used for ultraviolet imaging in a wire bonded package. ...

The LINEAR system alone has discovered 84,764 asteroids, as of August 28, 2007.[26] Between all of the automated systems, 4711 near-Earth asteroids have been discovered[27] including over 600 more than 1 km in diameter. The Lincoln Near-Earth Asteroid Research (LINEAR) project is a cooperative project between the United States Air Force, NASA and MITs Lincoln Laboratory for the systematic discovery of near-Earth asteroids. ... Near Earth Asteroid Tracking (NEAT) is a program run by NASA and Jet Propulsion Laboratory to discover near-Earth objects. ... Spacewatch is a project at the University of Arizona that specializes in the study of minor planets, and including various types of asteroids and comets. ... Lowell Observatory Near-Earth-Object Search (LONEOS) is a program run by NASA and Lowell Observatory to discover near-Earth objects. ... Catalina Sky Survey is a project to discover comets and asteroids, and to search for near_earth objects. ... Campo Imperatore Near-Earth Objects Survey (CINEOS) is a project that looks for near-earth objects. ... Japans National Space Development Agency (NASDA), the National Aeronautic Laboratory, and the Space and Technology Agency have allocated the necessary funds to bring the Japanese Spaceguart Association (JSGA)on-line. ... The Asiago-DLR Asteroid Survey (ADAS) is a project to search for comets and asteroids, with special emphasis on near_Earth objects. ... is the 240th day of the year (241st in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ...


Naming

Overview: naming conventions

A newly discovered asteroid is given a provisional designation (such as 2002 AT4) consisting of the year of discovery and an alphanumeric code indicating the half-month of discovery and the sequence within that half-month. Once an asteroid's orbit has been confirmed, it is given a number, and later may also be given a name (e.g. 433 Eros). The formal naming convention uses parentheses around the number (e.g. (433) Eros), but dropping the parentheses is quite common. Informally, it is common to drop the number altogether, or to drop it after the first mention when a name is repeated in running text. Provisional designation of in astronomy is the naming convention applied to astronomical objects immediately following their discovery. ... (also written 2002 AT4) is an as yet unnamed and un-numbered near-Earth asteroid. ... The asteroid 433 Eros (eer-os) was named after the Greek god of love Eros. ...


Asteroids that have been given a number but not a name keep their provisional designation, e.g. (29075) 1950 DA. As modern discovery techniques are finding vast numbers of new asteroids, they are increasingly being left unnamed. The first asteroid to be left unnamed was for a long time (3360) 1981 VA, now 3360 Syrinx; as of November 2006, this distinction is now held by (3708) 1974 FV1. On rare occasions, a small body's provisional designation may become used as a name in itself: the still unnamed (15760) 1992 QB1 gave its name to a group of Kuiper belt objects which became known as cubewanos. Asteroid 1950 DA, radar image (29075) 1950 DA is the near Earth object with the highest known possible probability of impacting Earth, according to the Palermo Technical Impact Hazard Scale. ... 3360 (1981 VA) is an Apollo and Mars crosser asteroid discovered in 1981. ... (3360) Syrinx (originally designated 1981 VA) is an Apollo and Mars crosser asteroid discovered in 1981. ... Provisional designation of in astronomy is the naming convention applied to astronomical objects immediately following their discovery. ... (15760) 1992 QB1 (also written (15760) 1992 QB1) was the first trans-Neptunian object to be discovered after Pluto and Charon. ... The Kuiper belt, derived from data from the Minor Planet Center. ... A cubewano is any substantial Kuiper belt object, orbiting beyond about 41 AU and not controlled by resonances with the outer planets. ...


Numbering

Asteroids are awarded with an official number once their orbits are confirmed. With the increasing rapidity of asteroid discovery, asteroids are currently being awarded six-figure numbers. The switch from five figures to six figures arrived with the publication of the Minor Planet Circular (MPC) of October 19, 2005, which saw the highest numbered asteroid jump from 99947 to 118161. This change caused a small Y2K-like crisis for various automated data services, since only five digits were allowed in most data formats for the asteroid number. Most services have now widened the asteroid number field. For those which did not, the problem has been addressed in some cases by having the leftmost digit (the ten-thousands place) use the alphabet as a digit extension. A=10, B=11,..., Z=35, a=36,..., z=61. A high number such as 120437 is thus cross-referenced as C0437 on some lists. The Minor Planet Circulars (MPCs) (also known as Minor Planets and Comets) are published generally on the date of each full moon by the Minor Planet Center. ... is the 292nd day of the year (293rd in leap years) in the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... This article is about the millennial computer glitch. ...


Sources for names

The first few asteroids were named after figures from Graeco-Roman mythology, but as such names started to dwindle the names of famous people, literary characters, discoverer's wives, children, and even television characters were used. This is a list of named asteroids, with links to the Wikipedia articles on the people, places, characters and concepts that they are named after. ... Classical mythology usually refers to the religious legends and practices of classical antiquity: Greek mythology; Roman mythology; Greek religion; and Roman religion. ...


The first asteroid to be given a non-mythological name was 20 Massalia, named after the city of Marseilles. For some time only female (or feminized) names were used; Alexander von Humboldt was the first man to have an asteroid named after him, but his name was feminized to 54 Alexandra. This unspoken tradition lasted until 334 Chicago was named; even then, oddly feminised names show up in the list for years afterward. 20 Massalia is a large and fairly bright Main belt asteroid. ... City flag Coat of arms Motto: By her great deeds, the city of Massilia shines The Old Port of Marseille Location Time Zone CET (GMT +1) Coordinates Administration Country Region Provence-Alpes-Côte dAzur Department Bouches-du-Rhône (13) Subdivisions 16 arrondissements (in 8 secteurs) Intercommunality Urban... An 1859 portrait of Alexander von Humboldt by the artist Julius Schrader, showing Mount Chimborazo in the background. ... 54 Alexandra is a very large and dark main belt asteroid. ... 334 Chicago is a very large Main belt asteroid. ...


As the number of asteroids began to run into the hundreds, and eventually the thousands, discoverers began to give them increasingly frivolous names. The first hints of this were 482 Petrina and 483 Seppina, named after the discoverer's pet dogs. However, there was little controversy about this until 1971, upon the naming of 2309 Mr. Spock (the name of the discoverer's cat). Although the IAU subsequently banned pet names as sources, eccentric asteroid names are still being proposed and accepted, such as 4321 Zero, 6042 Cheshirecat, 9007 James Bond, 13579 Allodd, 24680 Alleven, or 26858 Misterrogers. 482 Petrina 482 Petrina is a minor planet orbiting Sun. ... 483 Seppina 483 Seppina is a minor planet orbiting Sun. ... 2309 Mr. ... IAU redirects here. ... Asteroid 9007 James Bond was discovered on 5 October 1983 by Antonin Mrkos at the Klet Observatory in the Czech Republic. ... 26858 Misterrogers is a Main Belt asteroid named after beloved childrens television host Mister Rogers. ...


Special naming rules

Asteroid naming is not always a free-for-all: there are some types of asteroid for which rules have developed about the sources of names. For instance Centaurs (asteroids orbiting between Saturn and Neptune) are all named after mythological centaurs, Trojans after heroes from the Trojan War, and trans-Neptunian objects after underworld spirits. The centaurs are a class of icy planetoids that orbit the Sun between Jupiter and Neptune, named after the mythical race of centaurs. ... This article is about the mythological creatures. ... Image of the Trojan asteroids in front of and behind Jupiter along its orbital path. ... The fall of Troy, by Johann Georg Trautmann (1713–1769). ... A trans-Neptunian object (TNO) is any object in the solar system with all or most of its orbit beyond that of Neptune. ...


Another well-established rule is that comets are named after their discoverer(s), whereas asteroids are not. One way to circumvent this rule has been for astronomers to exchange the courtesy of naming their discoveries after each other. A particular exception to this rule is 96747 Crespodasilva, which was named after its discoverer, Lucy d'Escoffier Crespo da Silva, because she died shortly after the discovery, at age 22.[28][dubious ][29] A few objects are also cross-listed as both comets and asteroids, such as 4015 Wilson-Harrington and 107P/Wilson-Harrington. 96747 Crespodasilva is an asteroid. ... Comet Wilson-Harrington is a periodic comet (formally designated 107P/Wilson-Harrington). ... Comet Wilson-Harrington is a periodic comet (formally designated 107P/Wilson-Harrington). ...


Symbols

The first few asteroids discovered were assigned symbols like the ones traditionally used to designate Earth, the Moon, the Sun and planets. The symbols quickly became ungainly, hard to draw and recognise. By the end of 1851 there were 15 known asteroids, each (except one) with its own symbol(s).[30]

Asteroid Symbol
Ceres Old planetary symbol of Ceres Variant symbol of Ceres Sickle variant symbol of Ceres Other sickle variant symbol of Ceres
2 Pallas Old symbol of Pallas Variant symbol of Pallas
3 Juno Old symbol of Juno Other symbol of Juno
4 Vesta Old symbol of Vesta Old planetary symbol of Vesta Modern astrological symbol of Vesta
5 Astraea
6 Hebe
7 Iris
8 Flora
9 Metis
10 Hygiea
11 Parthenope
12 Victoria
13 Egeria Never assigned.
14 Irene "A dove carrying an olive-branch, with a star on its head," never drawn.[31]
15 Eunomia
28 Bellona
35 Leukothea
37 Fides

Johann Franz Encke made a major change in the Berliner Astronomisches Jahrbuch (BAJ, Berlin Astronomical Yearbook) for 1854. He introduced encircled numbers instead of symbols, although his numbering began with Astraea, the first four asteroids continuing to be denoted by their traditional symbols. This symbolic innovation was adopted very quickly by the astronomical community. The following year (1855), Astraea's number was bumped up to 5, but Ceres through Vesta would be listed by their numbers only in the 1867 edition. A few more asteroids (28 Bellona,[32] 35 Leukothea,[33] and 37 Fides[34]) would be given symbols as well as using the numbering scheme. The circle would become a pair of parentheses, and the parentheses sometimes omitted altogether over the next few decades.[31] Spectral type: G[8] Absolute magnitude: 3. ... Image File history File links Ceres_symbol. ... Image File history File links Ceres2. ... Image File history File links Ceres_symbol. ... Image File history File links Ceres3. ... 2 Pallas (pal-us, Greek Παλλάς) was the first asteroid discovered after 1 Ceres. ... Image File history File links 2Pallas_symbol. ... Image File history File links This is a lossless scalable vector image. ... Juno (IPA: ), designated 3 Juno in the Minor Planet Center catalogue system, was the third asteroid to be discovered and is one of the largest main belt asteroids, being the second heaviest of the stony S-type. ... Image File history File links Juno_symbol. ... Image File history File links 3_Juno_(1). ... Image File history File links Symbol_3. ... 4 Vesta (ves-ta) is the second most massive asteroid in the asteroid belt, with a mean diameter of about 530 km and an estimated mass 12% the mass of the entire asteroid belt. ... Image File history File links This is a lossless scalable vector image. ... Image File history File links This is a lossless scalable vector image. ... Image File history File links Vesta_symbol. ... Image File history File links This is a lossless scalable vector image. ... 5 Astraea (as-tree-a; written Astræa in the early scientific litterature) is a large main belt asteroid. ... Image File history File links This is a lossless scalable vector image. ... 6 Hebe (hee-bee, Greek ‘Ήβη) is a very large Main belt asteroid. ... Image File history File links This is a lossless scalable vector image. ... 7 Iris (eye-ris) is one of the largest main belt asteroids. ... Image File history File links This is a lossless scalable vector image. ... 8 Flora (flor-a) is a large, bright Main belt asteroid. ... Image File history File links This is a lossless scalable vector image. ... 9 Metis (mee-tis) is one of the largest Main belt asteroids. ... Image File history File links This is a lossless scalable vector image. ... 10 Hygiea (hye-jee-a or hi-jee-a) is the fourth largest Main belt asteroid with a diameter of 407 km. ... Image File history File links This is a lossless scalable vector image. ... 11 Parthenope (par THEN o pay) is a large, bright Main belt asteroid. ... Image File history File links This is a lossless scalable vector image. ... 12 Victoria is a large Main belt asteroid. ... Image File history File links This is a lossless scalable vector image. ... 13 Egeria (e GER ee a) is a large Main belt asteroid. ... 14 Irene (eye REE nee) is a very large Main belt asteroid. ... 15 Eunomia (ew-noh-mee-a) is the 12th largest Main belt asteroid. ... Image File history File links This is a lossless scalable vector image. ... 28 Bellona (be-loe-na, Latin Bellōna) is a large main belt asteroid. ... Image File history File links This is a lossless scalable vector image. ... 35 Leukothea is a large, dark main belt asteroid. ... Image File history File links 35_Leukothea_symbol. ... 37 Fides (IPA: ) is a large main belt asteroid. ... Image File history File links This is a lossless scalable vector image. ... Johann Franz Encke (23 September 1791 – 26 August 1865) was a German astronomer, born in Hamburg. ... 5 Astraea (as-tree-a; written Astræa in the early scientific litterature) is a large main belt asteroid. ... 28 Bellona (be-loe-na, Latin Bellōna) is a large main belt asteroid. ... 35 Leukothea is a large, dark main belt asteroid. ... 37 Fides (IPA: ) is a large main belt asteroid. ...


Exploration

Until the age of space travel, objects in the asteroid belt were merely pinpricks of light in even the largest telescopes and their shapes and terrain remained a mystery. The best modern ground-based telescopes, as well as the Earth-orbiting Hubble Space Telescope, can resolve a small amount of detail on the surfaces of the very largest asteroids, but even these mostly remain little more than fuzzy blobs. Limited information about the shapes and compositions of asteroids can be inferred from their light curves (their variation in brightness as they rotate) and their spectral properties, and asteroid sizes can be estimated by timing the lengths of star occulations (when an asteroid passes directly in front of a star). Radar imaging can yield good information about asteroid shapes and orbital and rotational parameters, especially for near-Earth asteroids. ISS in earth orbit. ... The Hubble Space Telescope (HST; also known colloquially as the Hubble or just Hubble) is a space telescope that was carried into Earth orbit by the Space Shuttle in April 1990. ... In astronomy, a light curve is a graph of light intensity as a function of time. ... For other uses, see Radar (disambiguation). ...


The first close-up photographs of asteroid-like objects were taken in 1971 when the Mariner 9 probe imaged Phobos and Deimos, the two small moons of Mars, which are probably captured asteroids. These images revealed the irregular, potato-like shapes of most asteroids, as did subsequent images from the Voyager probes of the small moons of the gas giants. Close Up is a half hour long New Zealand current affairs program produced by Television New Zealand. ... Mariner 9 launch Mariner 9 (Mariner Mars 71 / Mariner-I) was a NASA space probe orbiter that helped in the exploration of Mars and was part of the Mariner program. ... Phobos (IPA: or [ˈfoʊ.bəs]) (systematic designation: ) is the larger and closer of Mars two moons (the other being Deimos). ... Deimos (IPA or ; Greek Δείμος: Dread), is the smaller and outermost of Mars’ two moons, named after Deimos from Greek Mythology. ... This article is about the planet. ... Voyager Project redirects here. ... This article does not cite any references or sources. ...

951 Gaspra, the first asteroid to be imaged in close up.
951 Gaspra, the first asteroid to be imaged in close up.

The first true asteroid to be photographed in close-up was 951 Gaspra in 1991, followed in 1993 by 243 Ida and its moon Dactyl, all of which were imaged by the Galileo probe en route to Jupiter. Source : NASA File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Source : NASA File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... 951 Gaspra is an S-type asteroid that orbits very close to the inner edge of the asteroid belt. ... 951 Gaspra is an S-type asteroid that orbits very close to the inner edge of the asteroid belt. ... NASA image of 243 Ida. ... 243 Ida (left) and Dacytl (right), as photographed by Galileo. ... Galileo is prepared for mating with the IUS booster Galileo and Inertial Upper Stage being deployed after being launched by the Space Shuttle Atlantis on the STS-34 mission Galileo was an unmanned spacecraft sent by NASA to study the planet Jupiter and its moons. ... For other uses, see Jupiter (disambiguation). ...


The first dedicated asteroid probe was NEAR Shoemaker, which photographed 253 Mathilde in 1997, before entering into orbit around 433 Eros, finally landing on its surface in 2001. Artists conception of the NEAR Shoemaker spacecraft Near Earth Asteroid Eros as seen from the NEAR spacecraft. ... 253 Mathilde is a Main belt asteroid that was visited by the NEAR Shoemaker spacecraft on its way to asteroid 433 Eros. ... The asteroid 433 Eros (eer-os) was named after the Greek god of love Eros. ...


Other asteroids briefly visited by spacecraft en route to other destinations include 9969 Braille (by Deep Space 1 in 1999), and 5535 Annefrank (by Stardust in 2002). 9969 Braille is a small Mars-crosser asteroid that was discovered on May 27, 1992 by Eleanor F. Helin and Kenneth J. Lawrence at Palomar Observatory and named after Louis Braille, inventor of the reading system for the blind. ... The spacecraft Deep Space 1 was launched October 24, 1998 on top of a Delta II rocket. ... Image of 5535 Annefrank taken by the Stardust space probe 5535 Annefrank is an inner main belt asteroid, and member of the Augusta family. ... An artists rendering of Stardust (NASA image) The Stardust capsule with cometary and interstellar samples landed at the U.S. Air Force Utah Test and Training Range at 10:10 UTC (15 January 2006) in the Bonneville Salt Flats. ...


In September 2005, the Japanese Hayabusa probe started studying 25143 Itokawa in detail and may return samples of its surface to earth. The Hayabusa mission has been plagued with difficulties, including the failure of two of its three control wheels, rendering it difficult to maintain its orientation to the sun to collect solar energy. Following that, the next asteroid encounters will involve the European Rosetta probe (launched in 2004), which will study 2867 Šteins and 21 Lutetia in 2008 and 2010. For other uses, see Hayabusa (disambiguation). ... Image:25143 Itokawa 051101-2 ISAS-JAXA.jpg Hayabusa image of 25143 Itokawa. ... Conceptual drawing of the Rosetta orbiter and Philae lander Rosetta is a European Space Agency-led unmanned space mission launched in 2004 intended to study the comet 67P/Churyumov-Gerasimenko. ... 2867 Å teins is a small main-belt asteroid that was discovered in 1969 by N. S. Chernykh. ... 21 Lutetia (loo TET ee a) is a large Main belt asteroid, about 100 kilometers in diameter. ...


In September 2007, NASA launched the Dawn Mission, which will orbit the dwarf planet Ceres and the asteroid 4 Vesta in 2011-2015, with its mission possibly then extended to 2 Pallas. For other uses, see NASA (disambiguation). ... The Dawn Mission, launched on September 27, 2007, is NASAs mission to send a robotic space probe to the two most massive members of the asteroid belt: the asteroid Vesta and the dwarf planet Ceres. ... Spectral type: G[8] Absolute magnitude: 3. ... 4 Vesta (ves-ta) is the second most massive asteroid in the asteroid belt, with a mean diameter of about 530 km and an estimated mass 12% the mass of the entire asteroid belt. ... 2 Pallas (pal-us, Greek Παλλάς) was the first asteroid discovered after 1 Ceres. ...


It has been suggested that asteroids might be used in the future as a source of materials which may be rare or exhausted on earth (asteroid mining), or materials for constructing space habitats (see Colonization of the asteroids). Materials that are heavy and expensive to launch from earth may someday be mined from asteroids and used for space manufacturing and construction. 433 Eros is a stony asteroid in a near-Earth orbit Raw resources and minerals could be mined from an asteroid in space using a variety of methods. ... A pair of ONeill cylinders Interior of a Torus (doughnut-shaped) station A space habitat, also called space colony or orbital colony, is a space station intended as a permanent settlement rather than as a simple waystation or other specialized facility. ... It has been suggested that Colonization of Ceres be merged into this article or section. ... Space manufacturing is the production of manufactured goods in an environment outside a planetary atmosphere. ...


In fiction

Main article: Asteroids in fiction

Asteroids and asteroid belts are a staple of science fiction stories. Asteroids play several potential roles in science fiction: as places which human beings might colonize; as resources for extracting minerals; as a hazard encountered by spaceships travelling between two other points; and as a threat to life on Earth due to potential impacts. Asteroids and asteroid belts are a staple of science fiction stories. ...


See also

Look up asteroid in
Wiktionary, the free dictionary.

Wiktionary (a portmanteau of wiki and dictionary) is a multilingual, Web-based project to create a free content dictionary, available in over 151 languages. ... For other uses, see Asteroid (disambiguation). ... 433 Eros is a stony asteroid in a near-Earth orbit Raw resources and minerals could be mined from an asteroid in space using a variety of methods. ... BOOTES, the Burst Observer and Optical Transient Exploring System, is located in Southern Spain and makes use of two sets of wide-field cameras, 240 km apart. ... The centaurs are a class of icy planetoids that orbit the Sun between Jupiter and Neptune, named after the mythical race of centaurs. ... Artists impression of Pluto (background) and Charon (foreground). ... Artists impression of a major impact event. ... This is a list of numbered minor planets, nearly all of them asteroids, in sequential order. ... This is a list of asteroids named after important people: Science Physicists 1979 Sakharov (Andrei Sakharov) 2001 Einstein (Albert Einstein, mathematician and physicist) 2002 Euler (Leonhard Euler, mathematician and physicist) 2352 Kurchatov (Igor Kurchatov) 3905 Doppler (Christian Doppler) 3949 Mach (Ernst Mach) 4065 Meinel (Aden Meinel) 4716 Urey (Harold Urey... This is a list of asteroids named after places, organized by continent. ... List of asteroids List of comets See also Trans-Neptunian object Categories: Solar System ... The following is a collection of lists of noteworthy asteroids in the Solar system, sometimes also including minor planets beyond the orbit of Jupiter. ... This is a list of named asteroids, with links to the Wikipedia articles on the people, places, characters and concepts that they are named after. ... Mesoplanet is a term coined by Isaac Asimov to refer to planetary bodies with sizes smaller than Mercury but larger than 1 Ceres. ... Minor planets, or asteroids or planetoids, are minor celestial bodies of the Solar system orbiting the Sun (mostly Small solar system bodies) that are smaller than major planets, but larger than meteoroids (commonly defined as being 10 meters across or less[1]), and that are not comets. ... The Minor Planet Center operates at the Smithsonian Astrophysical Observatory (SAO), which is part of the Center for Astrophysics (CfA) along with the Harvard College Observatory (HCO). ... Near-Earth objects (NEO) are asteroids, comets and large meteoroids whose orbit intersects Earths orbit and which may therefore pose a collision danger. ... This page alphabetically lists the first thousand asteroids to be numbered, which are mostly in the main belt. ... Artists impression of a major impact event. ...

References

  1. ^ Beech, M.; Steel, D. I. (September 1995). "On the Definition of the Term Meteoroid". Quarterly Journal of the Royal Astronomical Society 36 (3): 281–284. Retrieved on 2006-08-31. 
  2. ^ Ceres, originally considered a new planet, was the largest asteroid known but is now classified as a dwarf planet. All other asteroids are now classified as small solar system bodies.
  3. ^ World Book at NASA
  4. ^ English Dictionary - Browsing Page P-44. HyperDictionary.com. Retrieved on 2008-04-15.
  5. ^ "Are Kuiper Belt Objects asteroids?", "Ask an astronomer", Cornell University
  6. ^ "Asteroids and Comets", NASA website
  7. ^ "Comet Dust Seems More Asteroidy" Scientific American, January 25, 2008
  8. ^ "Comet samples are surprisingly asteroid-like", New Scientist, 24 January 2008
  9. ^ Questions and Answers on Planets, IAU
  10. ^ "Three new planets may join solar system", New Scientist, 16 August 2006
  11. ^ JPL. How Many Solar System Bodies. JPL Solar System Dynamics. NASA. Retrieved on 2008-06-19.
  12. ^ Minor Planet Statistics. Minor Planet Center. Retrieved on 2008-06-19.
  13. ^ Minor Planet Names. Minor Planet Center. Retrieved on 2008-06-19.
  14. ^ Discovery Circumstances: Numbered Minor Planets (1)-(5000). Minor Planet Center. Retrieved on 2006-10-11.
  15. ^ Discovery Circumstances: Numbered Minor Planets (180001)-(185000). Minor Planet Center. Retrieved on 2008-06-19.
  16. ^ European Space Agency (April 4, 2002). "New study reveals twice as many asteroids as previously believed". Press release. Retrieved on 2008-02-21.
  17. ^ Krasinsky, G. A.; Pitjeva, E. V.; Vasilyev, M. V.; Yagudina, E. I. (July 2002). "Hidden Mass in the Asteroid Belt". Icarus 158 (1): 98–105. doi:10.1006/icar.2002.6837. 
  18. ^ Pitjeva, E. V. (2004). "Estimations of masses of the largest asteroids and the main asteroid belt from ranging to planets, Mars orbiters and landers". 35th COSPAR Scientific Assembly. Held 18-25 July 2004, in Paris, France: 2014. 
  19. ^ Zappalà, V.; Bendjoya, Ph.; Cellino, A.; Farinella, P.; Froeschle, C. (1995). "Asteroid families: Search of a 12,487-asteroid sample using two different clustering techniques". Icarus 116: 291–314. doi:10.1006/icar.1995.1127. Retrieved on 2007-04-15. 
  20. ^ Chapman, C. R.; Morrison, D.; Zellner, B. (1975). "Surface properties of asteroids: A synthesis of polarimetry, radiometry, and spectrophotometry". Icarus 25: 104–130. doi:10.1016/0019-1035(75)90191-8. 
  21. ^ Tholen, D. J. (March 8-11, 1988). "Asteroid taxonomic classifications". Asteroids II; Proceedings of the Conference: pp. 1139-1150, Tucson, AZ: University of Arizona Press. Retrieved on 2008-04-14. 
  22. ^ Bus, S. J.; Binzel, R. P. (2002). "Phase II of the Small Main-belt Asteroid Spectroscopy Survey: A feature-based taxonomy". Icarus 158: 146. doi:10.1006/icar.2002.6856. 
  23. ^ McSween Jr., Harry Y. (1999). Meteorites and their Parent Planets, 2nd edition, Oxford University Press. ISBN 0521587514. 
  24. ^ Chapman, Mary G. (May 17, 1992). Carolyn Shoemaker, Planetary Astronomer and Most Successful 'Comet Hunter' To Date. USGS. Retrieved on 2008-04-15.
  25. ^ Yeomans, Don. Near Earth Object Search Programs. NASA. Retrieved on 2008-04-15.
  26. ^ Minor Planet Discover Sites. Retrieved on 2007-08-31.
  27. ^ Unusual Minor Planets. Retrieved on 2007-08-31.
  28. ^ Citation from MPC 55988. Retrieved on 2006-06-05.
  29. ^ Staff. "Lucy Crespo da Silva, 22, a senior, dies in fall", Hubble News Desk, November 28, 2000. Retrieved on 2008-04-15. 
  30. ^ Gould, B. A. (1852). "On the Symbolic Notation of the Asteroids". Astronomical Journal 2: 80. doi:10.1086/100212. 
  31. ^ a b Hilton, James L. (2001-09-17). When Did the Asteroids Become Minor Planets. Retrieved on 2006-03-26.
  32. ^ Encke, J. F. (1854). "Beobachtung der Bellona, nebst Nachrichten über die Bilker Sternwarte". Astronomische Nachrichten 38: 143. doi:10.1002/asna.18540380907. 
  33. ^ Rümker, G.; Peters, C. A. F. (1855). "Name und Zeichen des von Herrn R. Luther zu Bilk am 19. April entdeckten Planeten". Astronomische Nachrichten 40: 373. doi:10.1002/asna.18550402405. 
  34. ^ Luther, R. (1856). "Schreiben des Herrn Dr. R. Luther, Directors der Sternwarte zu Bilk, an den Herausgeber". Astronomische Nachrichten 42: 107. doi:10.1002/asna.18550420705. 

Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 243rd day of the year (244th in leap years) in the Gregorian calendar. ... Artists impression of Pluto (background) and Charon (foreground). ... A Small Solar System Body (SSSB) is a term defined in 2006 by the International Astronomical Union to describe objects in the Solar System that are neither planets nor dwarf planets: [1] This encompasses: all minor planets apart from the dwarf planets, : the classical asteroids, (except for 1 Ceres, the... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Common Era (or Anno Domini), in accordance with the Gregorian calendar. ... is the 105th day of the year (106th in leap years) in the Gregorian calendar. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Common Era (or Anno Domini), in accordance with the Gregorian calendar. ... is the 170th day of the year (171st in leap years) in the Gregorian calendar. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Common Era (or Anno Domini), in accordance with the Gregorian calendar. ... is the 170th day of the year (171st in leap years) in the Gregorian calendar. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Common Era (or Anno Domini), in accordance with the Gregorian calendar. ... is the 170th day of the year (171st in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 284th day of the year (285th in leap years) in the Gregorian calendar. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Common Era (or Anno Domini), in accordance with the Gregorian calendar. ... is the 170th day of the year (171st in leap years) in the Gregorian calendar. ... is the 94th day of the year (95th in leap years) in the Gregorian calendar. ... Also see: 2002 (number). ... For information on Wikipedia press releases, see Wikipedia:Press releases. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Common Era (or Anno Domini), in accordance with the Gregorian calendar. ... is the 52nd day of the year in the Gregorian calendar. ... Georgij A. Krasinsky is a Russian astronomer active at the Institute of Applied Astronomy, Russian Academy of Science, St Petersburg. ... Elena Vladimirovna Pitjeva is a Russian theoretical physicist at the Institute of Applied Astronomy, Russian Academy of Sciences, St. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... Elena Vladimirovna Pitjeva is a Russian theoretical physicist at the Institute of Applied Astronomy, Russian Academy of Sciences, St. ... The Eiffel Tower has become the symbol of Paris throughout the world. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 105th day of the year (106th in leap years) in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Common Era (or Anno Domini), in accordance with the Gregorian calendar. ... is the 104th day of the year (105th in leap years) in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... is the 137th day of the year (138th in leap years) in the Gregorian calendar. ... Year 1992 (MCMXCII) was a leap year starting on Wednesday (link will display full 1992 Gregorian calendar). ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Common Era (or Anno Domini), in accordance with the Gregorian calendar. ... is the 105th day of the year (106th in leap years) in the Gregorian calendar. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Common Era (or Anno Domini), in accordance with the Gregorian calendar. ... is the 105th day of the year (106th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 243rd day of the year (244th in leap years) in the Gregorian calendar. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 243rd day of the year (244th in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 156th day of the year (157th in leap years) in the Gregorian calendar. ... is the 332nd day of the year (333rd in leap years) in the Gregorian calendar. ... Year 2000 (MM) was a leap year starting on Saturday. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Common Era (or Anno Domini), in accordance with the Gregorian calendar. ... is the 105th day of the year (106th in leap years) in the Gregorian calendar. ... Benjamin Apthorp Gould (September 27, 1824 – November 26, 1896) was an American astronomer. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... James Lindsay Hilton (born February 21, 1957) has been an astronomer at the United States Naval Observatory since 1986. ... This article is about the year. ... is the 260th day of the year (261st in leap years) in the Gregorian calendar. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... March 26 is the 85th day of the year (86th in leap years) in the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ...

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A Small Solar System Body (SSSB) is a term defined in 2006 by the International Astronomical Union to describe objects in the Solar System that are neither planets nor dwarf planets: [1] This encompasses: all minor planets apart from the dwarf planets, : the classical asteroids, (except for 1 Ceres, the... Vulcanoids are hypothetical asteroids that may orbit in a dynamically stable zone between 0. ... Computer model of the Apollo Asteroid 6489 Golevka Near-Earth asteroids (NEAs) are asteroids whose orbits are close to Earths orbit. ... For other uses, see Asteroid (disambiguation). ... Image of the Trojan asteroids in front of and behind Jupiter along its orbital path. ... The centaurs are a class of icy planetoids that orbit the Sun between Jupiter and Neptune, named after the mythical race of centaurs. ... Damocloids are asteroids such as 5335 Damocles and 1996 PW that have Halley family or long-period highly eccentric orbits typical of periodic comets such as Comet Halley, but without showing a cometary coma or tail. ... As of March 2007, there are five[1] known Neptune Trojans (named by analogy to the Trojan asteroids) which have the same orbital period as the planet. ... Minor planet is the official term for asteroids and trans-Neptunian objects. ... Minor planet is the official term for asteroids and trans-Neptunian objects. ... 243 Ida and its moon Dactyl An asteroid moon is an asteroid that orbits another asteroid. ... Comet Hale-Bopp Comet West For other uses, see Comet (disambiguation). ... A trans-Neptunian object (TNO) is any object in the solar system that orbits the sun at a greater distance on average than Neptune. ... The Kuiper belt, derived from data from the Minor Planet Center. ... A scattered disk object (or scattered disc object or SDO) is a trans-Neptunian object of the Kuiper belt with a very eccentric orbit. ... Artists rendering of the Oort cloud and the Kuiper Belt. ... Minor planets, or asteroids or planetoids, are minor celestial bodies of the Solar system orbiting the Sun (mostly Small solar system bodies) that are smaller than major planets, but larger than meteoroids (commonly defined as being 10 meters across or less[1]), and that are not comets. ... Meteor redirects here. ... List of asteroids List of comets See also Trans-Neptunian object Categories: Solar System ... 243 Ida & Dactyl. ... Near-Earth objects (NEO) are asteroids, comets and large meteoroids whose orbit intersects Earths orbit and which may therefore pose a collision danger. ... Artists impression of Pluto (background) and Charon (foreground). ... This article is about the astronomical term. ... This article is about the Solar System. ... This page alphabetically lists the first thousand asteroids to be numbered, which are mostly in the main belt. ... This is a list of named asteroids, with links to the Wikipedia articles on the people, places, characters and concepts that they are named after. ...


  Results from FactBites:
 
Asteroid Introduction (543 words)
Sixteen asteroids have a diameter of 240 km or greater.
Asteroids that are on a collision course with Earth are called meteoroids.
Then on October 1991 asteroid 951 Gaspra was visited by the Galileo spacecraft and became the first asteroid to have hi-resolution images taken of it.
Asteroid - Wikipedia, the free encyclopedia (3553 words)
Asteroids are commonly classified into groups based on the characteristics of their orbits and on the details of the spectrum of sunlight they reflect.
Stories of asteroid mining became more and more numerous since the late 1940s, with the next logical step being depictions of a society on terraformed asteroids —in some cases dug under the surface, in others having dome colonies and in still others provided with an atmosphere which is kept in place by an artificial gravity.
Moreover, depictions of the Asteroid Belt as The New Frontier clearly draw (sometimes explicitly) on the considerable literature of the Nineteenth-Century Frontier and the Wild West.
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