Cometary Activity in Near-Earth Asteroid (3552) Don Quixote

The near-Earth object (NEO) population is thought to comprise a number of "dormant" short-period comets [1]. One of the most promising NEO candidates for a cometary origin is (3552) Don Quixote, due to its comet-like orbit and albedo. We present the discovery of cometary activity in (3552) Don Quixote based on thermal-infrared obser- vations made with the Spitzer Space Telescope. Our observations clearly show the presence of a coma and a tail which we identify as molecular line emission from CO2 and thermal emission from dust. Our discovery indicates that more NEOs may harbor volatiles than previously expected.