Topic summary
1998 WW31

1998 WW31 is a non-resonant trans-Neptunian object and binary system from the Kuiper belt located in the outermost region of the Solar System, approximately 148 kilometers (92 miles) in diameter. It was first observed on 18 November 1998, by American astronomer Marc Buie and at the Kitt Peak National Observatory in Arizona, United States. In December 2000, a minor-planet moon, designated S/2000 (1998 WW31) 1 with a diameter of 123 kilometers (76 miles), was discovered in its orbit. After Charon in 1978, it was the first of many satellites since discovered in the outer Solar System.