A survey of the entire sky in three near-infrared wave bands (J, H, and K) carried out jointly by the University of Massachusetts and the Infrared Processing and Analysis Center (IPAC) of the California Institute of Technology (Caltech). Two identical 1.3-m reflectors were used, one at the Fred Lawrence Whipple Observatory in Arizona and the other at Cerro Tololo Inter-American Observatory in Chile. The northern survey started in 1997 and the southern in 1998; both were completed in 2001, and the 2MASS All-Sky Catalog was released in 2003, containing positions and photometry for 470 992 970 objects.
http://www.ipac.caltech.edu/2mass/ Official project website with numerous images.
Subjects: Astronomy and Astrophysics.