This article was automatically translated from the original Turkish version.

Kuiper Belt

The Kuiper Belt is a flat ring of icy bodies orbiting beyond the orbit of Neptune around Sun. It is named after Dutch-American astronomer Gerard P. Kuiper and consists of hundreds of millions of objects whose orbits lie close to the plane of the solar system and are thought to be remnants from the formation of the outer planets. The Kuiper Belt is believed to be the source of most observed short-period comets, particularly those with orbital periods shorter than 20 years around the Sun and those with orbits in the region of work planets, including icy Centaur objects. Although its existence had been theorized for decades, the Kuiper Belt was not detected until the 1990s, when large telescopes and sensitive light detectors became available.

Objects in the Kuiper Belt orbit at an average distance greater than Neptune’s mean orbital distance (approximately 30 astronomical units (AU), or 4.5 billion kilometers) from the Sun. The outer edge of the Kuiper Belt is less clearly defined but is nominally taken to exclude objects that come closer than 47.2 AU (7.1 billion kilometers) to the Sun, corresponding to the 2:1 Neptune resonance where an object completes one orbit for every two orbits of Neptune. The Kuiper Belt includes large bodies such as Eris, Pluto, Makemake, Haumea, Quaoar like and likely millions of smaller icy bodies ear (of grain).

Discovery of the Kuiper Belt

Irish astronomer Kenneth E. Edgeworth proposed in 1943 that the distribution of small bodies in the solar system was not limited to the current distance of Pluto. In 1951, Kuiper developed a stronger argument. Based on an analysis of the mass distribution of objects needed to form planets during the solar system’s formation, Kuiper showed that a large reservoir of small icy remnants—active comet nuclei—must exist beyond Neptune. Dutch astronomer Jan Oort proposed the existence of a much more distant spherical reservoir of icy bodies, now called the Oort Cloud, which continuously replenishes comets. His hypothesis adequately explained the origin of long-period comets (those with periods longer than 200 years). However, Kuiper noted that the many short-period comets (20 years or less), which orbit the Sun in the same direction and near the plane of the solar system, required a closer, flatter source. This explanation, clearly restated in 1988 by American astronomer Martin Duncan and work colleagues, remained the strongest argument for the Kuiper Belt’s existence until its direct detection.

Oort Cloud

The Oort Cloud has never been observed directly, but it is believed to contain a spherical distribution of icy objects orbiting the Sun at distances between 3,000 and 100,000 AU. It is also widely accepted that the majority of long-period comets in the solar system originate from this cloud. The objects in the Oort Cloud are thought to have formed closer to the Sun, near the current orbits of the planets, and were later scattered to their present locations by gravitational interactions with the planets. Astronomers theorize that the Oort Cloud contains approximately 10¹² to 10¹³ members with a total mass of about 100 World masses. Objects in the Kuiper Belt are affected by planetary gravity. At greater distances, between 50 and 2,000 AU, objects are largely unaffected by the planets and form the inner Oort Cloud. Between 2,000 and 15,000 AU, objects are influenced by galactic tidal forces, and in the outer Oort Cloud, from 15,000 to 100,000 AU, objects are perturbed by the gravity of nearby stars. Beyond the Oort Cloud, the Sun’s gravity is too weak to hold objects in orbit.