The Kuiper belt is named after Gerar Kuiper, an American astronomer who founded the Lunar and Planetary Laboratory in Arizona in 1960 and who gave his name to this doughnut-shaped area beyond Neptune located on the outer edges of our planet. Solar system. It was in 1951 , when Kuiper predicted the existence of a belt of icy objects at the far end of the solar system. He never found out; it would be many more years before this remote region of the solar system was officially discovered.
It is made, like the asteroid belt, of debris from the early history of the solar system and, like the Oort cloud, is thought to be a source of comets. Of course, it was not until 1992 when scientists managed to discover it. It was astronomers Dave Jewitt and Jane Luu who had been “doggedly scanning the skies for faint objects beyond Neptune” since 1987.
Well-known objects in the belt
It is mainly made up of icy objects, dwarf planets, dust, and comets. With temperatures only a few tens of degrees above absolute zero, even volatile ices like carbon monoxide that can’t survive near the Sun freeze in the Kuiper belt.
Here we will find Pluto, the most famous of the objects that float in the Kuiper belt . This dwarf planet with a radius of 1,188 kilometers was discovered in February 1930 by the American astronomer Clyde William Tombaugh. It is considered the first true Kuiper belt object. Much later, more evidence for the existence of the Kuiper belt emerged from the study of comets.
Sedna is another of the icy worlds in the Kuiper belt. It is about three-quarters the size of Pluto and was discovered in 2004. It is so far from the sun that it takes about 10,500 years to make a single orbit. It is about 1,770 kilometers wide.
And we also have Arrokoth and what we previously knew as Ultima Thule. Located about 6.4 billion kilometers from Earth, it became the most distant and primitive world in the solar system visited by a spacecraft: NASA’s New Horizons. Its surface is covered with methanol ice and other indeterminate organic molecules that give it a reddish color and it orbits around the Sun, with its -233 ºC , at about 44.2 astronomical units (or 6,600 million kilometers). It is made up of two flattened lobes joined at the edges, as it is barely 10 kilometers wide (and 36 km long).
And Eris , a little smaller than Pluto (which has a small moon called Dysnomia) or Haumea which, shaped like a flattened American football, also has two moons, Hi’iaka and Namaka.
There are billions of icy objects there
But these objects are accompanied by probably millions of icy objects, collectively referred to as Kuiper belt objects (KBOs) or trans-Neptunian objects (TNOs), in this distant region of our solar system.
The Kuiper belt, a huge frozen deposit that contains the most primitive material in the Solar System, is very far away, so we need more studies of these distant objects to know, for example, their composition and particularities. We know that the orbits of its objects fall into several distinct groups. As University of Arizona dynamicist Renu Malhotra discovered, resonant orbits avoid close and destabilizing encounters with Neptune, allowing resonant Kuiper belt objects to persist, since they never run into larger objects.
Now 50 times farther from the Sun than Earth, New Horizons – launched in 2006 – continues to explore this particular corner of the solar system, from a unique location and giving us observations we can’t make from anywhere else. The spacecraft still has fuel left to visit another Kuiper belt object, so “there’s a bright future ahead,” New Horizons principal investigator Alan Stern said.
Reference: “The solar nebula origin of (486958) Arrokoth, a primordial contact binary in the Kuiper belt” by WB McKinnon et al; “The geology and geophysics of the Kuiper Belt object (486958) Arrokoth” by JR Spencer et al; “Color, composition, and thermal environment of Kuiper Belt object (486958) Arrokoth” by WM Grundy et al. Science, February 2020.
NASA Kuiper Belt website
