Asteroid 944, discovered in 1920 by W. Baade. It is of D class, and its diameter is 38 km. Hidalgo has a highly elliptical 13.8-year orbit that carries it from perihelion at 1.95 AU, at the inner edge of the main asteroid belt, out to aphelion at 9.53 AU, the distance of Saturn; the semimajor axis is 5.742 AU. Until the discovery of Chiron in 1977, it had the greatest aphelion distance and longest period of any known asteroid. Its orbit, which has the unusually high inclination of 42°.6, is similar to those of periodic comets, and it could be an extinct cometary nucleus.
Subjects: Astronomy and Astrophysics.