3552 Don Quixote

3552 Don Quixote, provisionally designated 1983 SA, is an exceptionally eccentric asteroid classified as a near-Earth object of the Amor group and also categorized as a Mars-crosser and Jupiter-crosser. It was discovered on September 26, 1983, by Swiss astronomer Paul Wild at Zimmerwald Observatory in Switzerland. The asteroid was named after the protagonist of Miguel de Cervantes' novel "Don Quixote," with its official naming citation published by the Minor Planet Center on December 2, 1990.

Characterized as a dark D-type asteroid according to Tholen and SMASS taxonomies, Don Quixote has a highly inclined orbit of 31 degrees, frequently perturbed by Jupiter. Measuring 18.4 kilometers in diameter with a rotation period of 7.7 hours, it was initially suspected to be an extinct comet due to its comet-like orbit and albedo. However, infrared observations using the Spitzer Space Telescope revealed faint cometary activity, including a tail observed in visible wavelengths for the first time in March 2018. This recurrent cometary behavior indicates that Don Quixote is likely a weakly active comet, with carbon dioxide molecular band emission inferred as the source of its activity.