Kuiper Belt
The Kuiper Belt is a circumstellar disc in the Solar System beyond the planets, extending from the orbit of Neptune (at 30 AU) to approximately 50 AU from the Sun. It is similar to the asteroid belt, but it is far larger—20 times as wide and 200 times as massive. Like the asteroid belt, it consists mainly of small bodies or remnants from the Solar System’s formation. Although many asteroids are composed primarily of rock and metal, most Kuiper Belt objects are composed largely of frozen volatiles (gases with low boiling points), such as methane, ammonia and water. The Kuiper Belt is home to three officially recognized dwarf planets: Pluto, Haumea and Makemake. A fourth dwarf planet, Eris, resides in scattered disc which lies beyond the Kuiper Belt.
The first observations of objects now known to reside in the Kuiper Belt were made in 1930 by Kenneth Edgeworth and Gerald Kuiper while independently examining data gathered during a meteor shower. These observations led them both to suggest that a large population of small planetary bodies existed beyond Neptune’s orbit; however their calculations differed by several orders of magnitude. In 1951–52 Gerard Kuiper conducted two surveys for faint blue stars that revealed his eponymous belt contained about twice as much material as Edgeworth had estimated, comparable in mass to Mars. Over subsequent decades many other astronomers have made discoveries within what would ultimately become known as “the Edgeworth-Kuiper belt”. Objects found include detached objects (“cubewanos”), resonant trans-Neptunian objects (TNOs placed in orbital resonance with Neptune), scattered disk objects (SDOs), and sednoids (extremELY distant TNOs). By 2008 over 1000 individual TNOs had been discovered, and more than 70 thousand smaller icy bodies. These discoveries have shown that Edgeworth’s original estimate was substantially correct: recent estimates place its total mass at 0.001% or 1/200th, respectively, that of Earth or Jupiter – still considerably more than thought when it was first proposed. Two bridges between these populations – called “resonance sticking” regions – appear to exist:: one connecting cubewanos near 44 AU with SDOs near 60 AU; another connecting Oort cloud comets passing through perihelion at 35 AU with cubewanos near 47–49 AU on either side along an elliptical “necklace”.
The existence of orbiting debris beyond Neptune has been hypothesized since 1841,:695 when John Couch Adams began investigating perturbations to Uranus’ orbit.:156 His calculations showed that they could be explained by the influence of an unseen planet lying beyond Uranus.:162 Adams predicted this new planet would have an orbit with a semi-major axis somewhere between 35–50 AU but no less than 42AU; he suggested it be named “Georgium Sidus” after King George III.:163 In 1893 Percival Lowell published his book entitled Mars As The Abode Of Life in which he speculated fireballs seen on Earth were actually caused by volcanic eruptions on Mars.:193 Based on his perceived pattern of movement,:194 Lowell incorrectly concluded they followed elliptical orbits centered on our Sun with aphelia ranging from 35–50AU; he dubbed this region “the zone of avoidance”.:195 Given Lowell’s insistence there must be another planet inside this zone he searched for it using some powerful telescopes he built himself but never found anything significant enough for him to announce discovery… In 1930 both Kenneth Edgeworth(independently))and Gerard Kuiper(building upon work done earlier by Jakob Ackeret)began speculating vast clouds filled with icy Planetesimals might exist well past Pluto based partly uponEdgeworth’s dynamical studies involving Meteor Stream interactions & cometary spectra suggesting high albedos & volatile compositions . Both men realized identifying any actual object out there would require very careful measurements indeed given their distances & lack thereof visible light compared w/nearby background stars making detection all but impossible without expensive dedicated equipment like CCD cameras not available until 1970s . Nevertheless each continued analyzing data hoping something might turn up eventually & finally did: On October 1st , 1992 Robert Hulseman& David Jewitt working @ Mauna Kea Observatory spotted 1992 QB1 using CCD camera becoming 1st Trans Neptunian Object(TNO) confirmed since Pluto 75yrs earlier! . Further refinements allowed additional fainter TNOsto be imaged resulting numerous detections throughout 1990s giving rise title “decadeof discoveries” culminating 1999 announcement ORBITAL ELEMENTS OF 699 OUTER SOLAR SYSTEM OBJECTS BY JEWITT ET AL.. This article provides list current best estimates physical & orbital parameters all stable non plutino TNOsas 2016 Oct 12 including 45 newly discovered 2015 Apr 27 -2016 Aug 25 timeframe .