(508338) 2015 SO20 is an extreme trans-Neptunian object and extended scattered disc object from the outermost region of the Solar System, approximately 220 kilometers (140 miles) in diameter.
This minor planet was first observed as 2010 TF182 on 8 October 2010, by American astronomer Megan Schwamb at ESO's La Silla Observatory in northern Chile.
Its orbit has an eccentricity of 0.79 and an inclination of 23° with respect to the ecliptic.
Based on an absolute magnitude of 6.5 and an assumed albedo of 0.09, the Johnston's Archive calculated a mean-diameter of 222 kilometers.
[4] Michael Brown estimates an albedo of 0.08 with a diameter of 221 kilometers using an absolute magnitude of 6.7.