Sedna

90377 Sedna (or Sedna or 2003 VB₁₂, its provisional designation) is an extreme Kuiper Belt object (a KBO with high eccentricity and orbital inclination) with an aphelion of 937 AU (18 times that of Pluto), and a perihelion of 76 AU (about 1.5 times Pluto's furthest distance). Its orbital period is about 11400 years. It is now on the way to its perihelion, due to reach it in 2076, currently (as of June 2025) about 83 AU from the Sun. At the time of discovery, it was the most distant solar system object under observation. Some current theories regarding a Planet Nine aim to explain the orbital inclination of Sedna and similar objects. Some research has been carried out as to the viability of a flyby mission this century.