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Kuiper Belt

Our solar system and its objects

 Automatic translation  Automatic translation Updated June 01, 2013

The solar system is actually much more complex than it appears if one considers that its gravitational influence extends up to 150 000 au. A considerable number of small icy objects, similar in size to that of asteroids, are in the Kuiper Belt and beyond, in the Oort cloud. The Kuiper Belt invented in 1951 by Dutch astronomer Gerard Kuiper, extends from the orbit of Neptune located to 30 au to about 100 au. Beyond 50 au, the number of objects greatly reduces this limit is known as the « Kuiper cliff ».
They are called trans-Neptunian objects or « ice dwarf » is also the source of short-period comets. Since the discovery of the first object in 1992, the number of objects discovered in the Kuiper belt has surpassed the thousand and is thought to contain more than 70,000 bodies from more than 100 km in diameter. This ring consists mainly of small bodies is 20 times larger than the asteroid belt between Mars and Jupiter. Kuiper Belt objects is also home to several hundred kilometers called « dwarf planets ».


Among these there are dwarf planets, Eris (≈2600 km), Pluto (≈2300 km), Makemake (1300 to 1900 km), Haumea (1960 x 1500 x 1000 km), Ixion (≈759 km), Varuna (840 to 1240 km), Quaoar (≈1250 km)...

Image: On the picture cons, the objects of the Kuiper Belt are green, orange objects scattered in the ring is about 30 AU from the Sun and covers an area of 20 AU. Credit: Minor Planet Center

NB: The Oort cloud could be about 50 000 AU, well beyond the Kuiper Belt, and contain many billions of nuclei of comets of more than 1.3 km.
The data from Voyager 1 and 2, published in July 2008, reveal that the bubble formed by the solar wind around our planetary system would have the form of a balloon stretched and compressed to one of its ends.
 Kuiper Belt - solar system

Collisional families


The gravitational force is responsible for all kinds of shocks between cosmic objects, from minor skirmishes to large collisions.
It moves continually objects, which eventually collide. They are also tragic that these collisions that we owe our existence.
2003 EL61 is a member of the collisional family that runs beyond the planet Neptune in the Kuiper Belt. Collisional families are groups of objects moving around the Sun and have shapes and sizes very similar, they remain tightly clustered in the same orbit as they are from the same object. Objects from the same body are supposed to be the same material, so they were landmark. 2003 EL61 is one of the largest objects and the brightest of the Kuiper belt have formed a family. The original shock produced EL61 and a multitude of objects and in particular 2 moons. These objects stay together and continue to travel on a similar orbit, all in the same trajectory.


Collisional families are very difficult to find, astronomers spot them by looking at objects that have a common orbit. The family is the only EL61 collisional family discovered in the Kuiper Belt.
2003 EL61 and its family were probably born at the beginning of the creation of the solar system, during the great bombardment, at a time when crashes were very common. It is due to collisions that planets are built. A little later, there are 3.8 billion years, when the Late Heavy Bombardment was abated, the objects that were not aggregated into planets have to rest in the cemeteries of objects such as belt Kuiper.

Image: Hubble discovered the smallest object ever seen in the Kuiper Belt, the vast ring of icy debris that surrounds our solar system. This performance is remarkable because the object is located at 6.75 billion km, measuring 3200 m in diameter only.

 the smallest object in the Kuiper Belt

Dwarf planet 2003 EL61


Haumea is one of the largest members of a family called TNO (Trans-Neptunian Object). This object called 2003 EL61 first since his first appearance in a photograph dated 2003, was officially christened by the International Astronomical Union: Haumea. The discovery of Haumea is controversial and contested by two teams. Mike Brown and his team at Caltech discovered Haumea in December 2004, from pictures they have taken May 6, 2004. On July 20, 2005, they published a report announcing the discovery at a conference in September 2005. At that time, José Luis Ortiz Moreno and his team at the Instituto de Astrofísica de Andalucia in the Sierra Nevada Observatory in Spain, announced the discovery of Haumea pictures taken in March 2003. An email Ortiz in the MPC (Minor Planet Center) announced their discovery of the March 7, 2003, on the night of July 27, 2005. Haumea is the name of a goddess of fertility and childbirth in the mythology of the Hawaiian people. Members of CSBN (Committee on Small Body Nomenclature) of the IAU (International Astronomical Union) and WGPSN (Working Group for Planetary System Nomenclature) attributed to Haumea dwarf planet status. This small solar system object joins Pluto, Ceres, Eris and Makemake. In this group, it is now considered a plutoid, that is to say, a dwarf planet located beyond the orbit of Neptune.


The two moons of Haumea receive names Hi'iaka (formerly Rudolf), which legend says it was born through the mouth of the goddess, while Namaka (formerly Blitzen), is a water spirit from of his body. The choice of these names and the legend seems relevant because astronomers believe that the two small satellites were torn from Haumea as a result of collisions, frequently within the Kuiper Belt.
This star has a chaotic form oblong like a rugby ball and its mean diameter is estimated at between 1 960 and 2 500 km, just below that of Pluto. Haumea described in the Kuiper Belt, an eccentric orbit between 5.25 billion km and 7.70 billion miles. It is inclined at 28.21 ° and Haumea circled the Sun in 284.76 years.
Spectroscopic analysis and examination of orbital periods of its two satellites, show that Haumea is probably composed of rock and pure ice, which explains its high albedo (0.70).
Haumea is a turn on itself in about four hours, which is certainly no stranger to its oblong shape.

NB: TNO (Trans-Neptunian Object): the family of trans-Neptunian objects including the orbits and physical characteristics have a common origin, due to collisions of the first moments of the history of the solar system.

 planète naine Hauméa

Image: Artist image of Haumea and its moons Hi'iaka and Namaka. Credit: A. Feild (Space Telescope Science Institute)

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