3552 Don Quixote

3552 Don Quixote, provisionally designated, is an exceptionally eccentric asteroid, classified as a near-Earth object of the Amor group, Mars-crosser and Jupiter-crosser, as well as a weakly active comet.

Discovery and naming
The asteroid was discovered on 26 September 1983, by Swiss astronomer Paul Wild at Zimmerwald Observatory near Bern, Switzerland. It was named after the comic knight who is the eponymous hero of Cervantes' Spanish novel Don Quixote (1605). The approved naming citation was published by the Minor Planet Center on 2 December 1990 (M.P.C. 17466).

Orbit and characteristics
Don Quixote is characterized as a dark D-type asteroid in the Tholen and SMASS taxonomy.

It has a highly inclined comet-like orbit of 31 degrees that leads to frequent perturbations by Jupiter. Don Quixote measures 18.4 kilometres in diameter and has a rotation period of 7.7 hours. Due to its comet-like orbit and albedo, Don Quixote has been suspected to be an extinct comet. However, infrared observations with the Spitzer Space Telescope at 4.5 μm revealed a faint coma and tail around the object. The cometary activity is inferred by carbon dioxide molecular band emission. In March 2018 a tail was observed at visible wavelengths for the first time. The observation of cometary features during two apparitions suggests that cometary activity is recurrent and Don Quixote is most likely a weakly active comet.