Kuiper-belt object

The Pluto-Charon system raises additional questions because it lies within the Kuiper Belt, which extends about 20 AU (astronomical units about 3 x 109 km) beyond the orbit of Neptune. NASA s New Horizons space mission, launched in January 2006, should help provide a better understanding of the nature of Pluto and Charon, especially in relation to other Kuiper Belt Objects. 

For the present, knowledge of these two bodies is still somewhat limited and speculative. Earth-based observations and data provided by orbiting telescopes indicate that Pluto s atmosphere is very thin, with a pressure on the planet s surface of between three and 50 microbars (0.3-5 percent that of Earth s atmosphere). The maximum temperature observed in the upper atmosphere is 106 K (—167°C), and the most abundant gases present are expected to be nitrogen, methane, carbon monoxide, and species produced by the photolysis of these substances. 

The most abundant species on Pluto s surface appears to be nitrogen, followed by carbon monoxide, methane, and water ice, all of which occur in the solid state. Based on the planet s density, scientists predict that its interior consists of some type of hydrated silicate mixed with up to 30 percent water ice. 

Almost nothing is known about the composition of Charon s atmosphere or surface. The surface appears to be covered primarily with water ice. Spectral lines for other species have been detected but not identified as belonging to specific compounds. 

Where did the solar system come from How was the Sun born  

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Pluto, with a diameter of 2300 km, has now been demoted from the smallest planet to one of the largest Kuiper belt objects. Pluto and its satellite Charon could be considered a binary system because they are closer in size than any other known celestial pair in the solar system and the barycenter of their orbits does not lie within either body. There are also two smaller moons, Nix and Hydra. All four bodies are likely KBOs with similar compositions. Pluto has a thin atmosphere containing N2, with minor CH4, CO, and Ar. Curiously, the face of Pluto oriented towards Charon contains more methane ice, and the opposite face contains more nitrogen and carbon monoxide ice. 

Distinguish between comets, Kuiper Belt Objects (KBOs), and Oort cloud objects. 

Among places where condensates accreted into significant solid bodies, such as planets, habitable realms have always been rarer than places that were either too cold or too hot for life to exist. Much of our Solar System s mass is still far too hot for life. Most of the deep interiors of the gas giants and rocky planets are too hot, as is, of course, the Sun itself. Most of the surface area of solid bodies in the Solar System are too cold - the icy satellites of the outer planets and the myriad comets and Kuiper Belt Objects on the far outer fringes of the Solar System. In this sense, places like the surfaces of Earth and Mars and Europa s subsurface ocean are indeed very rare places. 

Sample returns from additional comets, outer main belt and Trojan asteroids, and Kuiper Belt objects representing distinct regions of the early Solar System. 

Kuiper Belt a region in the outer Solar System beyond Neptune s orbit populated by small icy planetesimals or Kuiper Belt objects, and dwarf planets. Many short-period comets (possessing orbits of less than 200 years) are thrown into the Solar System from the Kuiper Belt. 

Neptune s largest moon, Triton, was discovered within weeks of the discovery of the planet itself. It is one of the most distant objects in the solar system. Even the outermost planet, Pluto, and its moon, Charon, spend considerable time on their eccentric orbits closer to the Sun than Triton. Its nature remained a mystery until the advent of new astronomical methods in the 1970s and 1980s and the flyby of the Voyager 2 spacecraft in 1989. In many ways, it is a planetary body on the edge —on the outer edge of the main part of the solar system, and the inner edge of the realm of comets and the recently discovered Kuiper belt objects. As such, it shares some of the characteristics of the icy satellites of the rest of the outer solar system with some of the nature of the colder, more distant, cometary bodies. 

Like the Oort cloud, the Kuiper Belt was initially hypothetical but, due to its proximity, techniques were eventually developed so that the larger Kuiper Belt objects (KBOs) could be telescopically detected from Earth. In 1992 the first KBO was discovered by Jewitt and Luu (1993). It was a 23rd magnitude object with a diameter of —320 km at an average solar distance of 44 AU. By the end of 2002, over 700 KBOs had been discovered, over 500 since the beginning of 1999. The dramatic rise in detection was due to heroic... 

Davis D. R. and FarineUa P. (1997) Collisional evolution of Edgeworth-Kuiper Belt objects. Icarus 125, 50-60. 

Jewitt D. C. (2002) From Kuiper Belt object to cometary nucleus the missing ultrared matter. Astron. J. 123, 1039-1049. 

Korsakoff s syndrome Krebs cycle Kuiper belt objects Kuru... 

Solid N2, CH4, H2O, and CO have been found on Triton and Pluto, witli additional CO2 on Triton. The molecule N2 dominates both surfaces, and other molecules are trapped in an N2 matrix. The only molecule identified on Charon is H2O. Surface compositions of these two bodies are quite different from those of satellites of Jupiter, Saturn, and Uranus. The compositional relationsliip of Triton and Pluto to that of tlie Edgeworth-Kuiper belt objects, and to tlie comets, is still unclear. 

There are many icy bodies in addition to comets in the solar system they are icy satellites and Kuiper belt objects. Icy satellites of the Jupiter and Saturn systems were observed by spacecraft to clarify their densities and surface compositions. As a result, it is widely accepted that the main component of icy satellites is water ice, and the existence of water ice is confirmed by the observation of near infrared reflectance spectra. Icy satellites were revealed to have various surface morphologies and geologic activities depending on their origin and the thermal evolution process. Most of the icy satellites have densities from 1 to 2 g/cm which means that these bodies are a mixture of ices and silicates. Icy satellites were formed by collisional accretion of small porous bodies. These bodies could be ice-silicate mixture and the porosity was corrupted according to their growth. Therefore, impact properties of an ice-silicate mixture with various porosities are necessary to be clarified in order to study the formation process of icy satellites. I review systematic experimental results on impact of ice-silicate mixture in Section 3. 

Researchers have learned a vast amount of new information about Jupiter, Saturn, Uranus, Neptune, Pluto and the Kuiper Belt Objects in the last century. Improved terrestrial telescopes, the Hubble Space Telescope, and space explorations such as Voyager 1 and 2, Galileo, and Cassini have produced new data that will take astrochemists years to analyze and interpret, providing them with even more detailed information about the chemical composition of the atmospheres, satellites, surfaces, and other features of the outer planets and their associated bodies. 

We shall apply the above described theory to the motion of a small body (asteroid, Kuiper belt object, satellite) moving around the Sun in a nearly Keplerian, elliptic, orbit, and perturbed by a major planet. 

Low-albedo objects are diverse in opposition behavior. Actually, asteroids of the primitive P and F types, located mainly in the outer asteroid belt, show linear phase curves down to phase angles of 2° [49,50], The first tentative phase curves for other dark and distant Solar system objects, like Centaurs and trans-Neptunian (Kuiper Belt) objects, also show linear phase dependence at small phase angles. However their phase curve slope is at least twice as large as that of low-albedo asteroids [51], For both types of dark objects there is an indication of a veiy narrow opposition surge at sub-degree phase angles. 

The Kuiper Belt Home Page, maintained by David Jewett, one of the codiscoverers of the first known Kuiper belt object in 1992... 

Pluto - a Kuiper belt object ((KBO), considered to be a planet from its discovery in 1930 until 2006. It is named after the Greek god of the underworld. 

Pluto discovered (Clyde Tombaugh) Tombaugh observes a body one-fifth the mass of Earth s moon. Pluto comes to be regarded as the ninth planet of the solar system, but in 2006 it is reclassified as one of the largest-known Kuiper Belt objects, a dwarf planet. 

Eris (Mike Brown) Working with C. A. Trujillo and D. L. Rabinowitz, Brown discovers Eris, the largest known dwarf planet and a Kuiper Belt object. It is 27 percent more massive than Pluto, another large Kuiper Belt object. 

The Kuiper belt extends from about the orbit of Neptune (30 AU) to about 55 AU and even more. The first Kuiper Belt Object, KBO, was discovered in 1992, presently several thousand KBOs are known. Their total number is estimated over 70 000 for objects over 100 km in diameter. It can be compared with the asteroid belt which occurs between the orbits of Mars and Jupiter but there are two important differences ... 

Composition asteroid belt is mainly made of rocky matter Kuiper belt objects are mainly composed of ice, frozen volatiles, methane, ammonia and water. 

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