944 Hidalgo

944 Hidalgo (IPA: /hɨˈdælɡoʊ/ hi-dal'-goe) is an unusual asteroid, and has the longest orbital period (13.77 years) of any asteroid in the traditional asteroid belt. With a high eccentricity of 0.66, its perihelion of 1.95 AU takes it to the inner edge of the asteroid belt, while its aphelion of 9.54 AU takes it right out to Saturn's orbit, a characteristic normally associated with Saturn's family of comets. Some astronomers therefore suspect that it was once a comet. Strictly speaking, Hidalgo is a Saturn-grazer rather than a Saturn-crosser as its aphelion does not clear Saturn's. Hidalgo's severe orbital inclination of 43° is suspected to be the result of a close encounter with Jupiter. Its diameter is estimated to be 20 km. 944 Hidalgo was discovered by Walter Baade on October 31, 1920 at Bergedorf Observatory near Hamburg, Germany. German astronomers observed a total eclipse in Mexico on September 10, 1923 and had an audience with the president of Mexico, and in honour of this they named the asteroid after the Mexican hero Miguel Hidalgo y Costilla. It was one of five minor planets included in the 1993 study, Transition Comets -- UV Search for OH Emissions in Asteroids, which was research involving amateur astronomers who were permitted to make use of the Hubble Space Telescope.