Unusual asteroid 2020 SO: astrometric investigation of the American rocket booster that returned to near-Earth space

Abstract

In the frame of this study astrometric observations of an unusual object 2020 SO - a newly discovered asteroid that turned out to be a Centaur upper-stage booster from 1960s - during its two close approaches to the Earth in December, 2020 and February, 2021 were carried out using two telescopes of Pulkovo observatory. The orbit of the object in question was determined and its future orbital evolution was modelled.