The 2MASS Asteroid and Comet Survey

Abstract Over the course of three years, the Two Micron All Sky Survey (2MASS) will carry out a survey of the entire sky at J (1.25 μm), H (1.65 μm), and Ks (2.17 μm) from telescopes in the northern and southern hemispheres. The initial public release of the survey data spans the period between June 7, 1997, and January 30, 1998, and covers approximately 6% of the sky. Asteroids and comets having known orbits were identified on the basis of their predicted positions as part of the pipeline processing of the data. The 2MASS sources associated with asteroids and comets are being compiled into a 2MASS Asteroid Catalog and 2MASS Comet Catalog. These catalogs are now available and will be updated at regular intervals as the survey progresses. The initial catalogs contain observations of 1054 asteroids and 2 comets, respectively. Near-infrared colors of asteroids of different taxa are shown, and an attempt is made to derive a simple compositional map of the asteroid belt, which is in agreement with previous work. The color–color distributions of Koronis asteroid family members are found to be distinct from those of other families in this sample. It is suggested that the Koronis parent body was differentiated and that different mineralogies had segregated on spatial scales much larger than 10 km prior to its catastrophic disruption. Two asteroids exhibiting unusual colors are examined, and a cautionary note is sounded about interpreting the colors of individual asteroids without considering the possibility of contamination by a background source.