Detached object

Detached objects are a special group of small planets found far away from the Sun, in a part of space called the outer Solar System. These objects belong to a larger family known as trans-Neptunian objects, which orbit beyond the planet Neptune. What makes detached objects different is their distance from the Sun. They orbit so far out that the gravity of Neptune and other planets barely affects them, making them seem "detached" from the rest of the Solar System.

Unlike most other trans-Neptunian objects, which have been moved by the gravity of large planets like Neptune, detached objects stay in orbits that are far away from these influences. They have points of closest approach to the Sun that are much larger than those of other objects, such as Pluto, Makemake, and Eris. Because of this, scientists sometimes call them extended scattered disc objects, distant detached objects, or scattered–extended objects.

Scientists have found at least nine of these detached objects. The most famous one is Sedna, which is the largest, farthest, and best known. Objects like Sedna, with very large orbits and very distant points of closest approach to the Sun, are called sednoids. As of 2025, four sednoids are known, including 2012 VP113, Leleākūhonua, and 2023 KQ14. These objects show patterns in their orbits that might be caused by the pull of planets we have not yet discovered.

Orbits

Detached objects have orbits that stay very far from the Sun. Their closest points to the Sun are much larger than the farthest point of Neptune's orbit. These objects often have very stretched-out, long paths around the Sun, reaching up to a few hundred times the distance from the Earth to the Sun.

Scientists are still trying to understand how these objects got their unusual orbits. Some ideas include the pull of a passing star, a very far-off object about the size of a planet, or the movement of Neptune long ago. Another idea is the possible influence of a large, unseen planet far beyond Neptune.

Classification

Detached objects are a special group of objects far from the Sun in our Solar System. They belong to a larger group called trans-Neptunian objects (TNOs). Unlike most TNOs, detached objects have orbits that keep them far away from the planet Neptune. This distance means Neptune's gravity does not affect them much, making them seem "detached" from the rest of the Solar System.

These objects usually come closer to the Sun (perihelion) at a distance greater than 40 AU, which is much farther than Neptune's orbit. Because of this, they do not interact strongly with Neptune. Some scientists think these objects might be part of a region called the inner Oort cloud or a link between a group of objects called the scattered disc and the Oort cloud. Studying these objects helps us learn more about how the giant planets moved and how the Solar System formed.

Possible detached objects

See also: Sednoid and Extreme trans-Neptunian object

This is a list of objects found by discovery date that might be detached objects because they are not easily moved by Neptune's orbit. They are close to the Sun but still far enough to seem "detached" from the rest of the Solar System.

These objects have points where they get closest to the Sun (perihelion) more than 40 AU away and their average distance from the Sun (semi-major axis) is more than 47.7 AU away.

Some other objects are also thought to be detached objects, though they are a little closer to the Sun, with perihelion distances between 38–40 AU.