Discovery of Pluto
The orbit of each of the planets is slightly affected by the gravitational influences of the other planets. Discrepancies in the early 1900s between … See more

Given the apparent magnitude (>20) of all but the biggest trans-Neptunian objects, the physical studies are limited to the following: See more

Among the extreme trans-Neptunian objects are three high-perihelion objects classified as sednoids: 90377 Sedna, 2012 VP113, and 541132 Leleākūhonua. They are distant See more

1. ^ The literature is inconsistent in the use of the phrases "scattered disc" and "Kuiper belt". For some, they are distinct populations; for others, the scattered disk is part of the Kuiper belt, in which case the low-eccentricity population is called the "classical Kuiper … See more

According to their distance from the Sun and their orbital parameters, TNOs are classified in two large groups: the Kuiper belt objects (KBOs) and the scattered disc objects (SDOs). The diagram to the right illustrates the distribution of known trans-Neptunian objects … See more

The only mission to date that primarily targeted a trans-Neptunian object was NASA's New Horizons, which was launched in January 2006 and flew by the Pluto system in July 2015 and 486958 Arrokoth in January 2019.
In 2011, a design … See more

• Dwarf planet
• Mesoplanet
• Nemesis (hypothetical star)
• Planet Nine
• Sednoid
• Small Solar System body See more