The Two Micron All Sky Survey (2MASS) project is designed to close the gap between our current technical capability and our knowledge of the near-infrared sky. In addition to providing a context for the interpretation of results obtained at infrared and other wavelengths, 2MASS will provide direct answers to immediate questions on the large-scale structure of the Milky Way and the Local Universe.

To achieve these goals, 2MASS is uniformly scanning the entire sky in three near-infrared bands to detect and characterize point sources
brighter than about 1 mJy in each band, with signal-to-noise ratio
(SNR) greater than 10, using a pixel size of 2.0". This will achieve an 80,000-fold improvement in sensitivity relative to earlier surveys.

2MASS uses two new, highly-automated 1.3-m telescopes, one at Mt. Hopkins, AZ, and one at CTIO, Chile. Each telescope is equipped with a three-channel camera, each channel consisting of a 256x256 array of
HgCdTe detectors, capable of observing the sky simultaneously at J
(1.25 {mu}m), H (1.65 {mu}m), and Ks (2.17 {mu}m), to a 3{sigma}
limiting sensitivity of 17.1, 16.4 and 15.3mag in the three bands.

The 2MASS arrays image the sky while the telescopes scan smoothly in declination at a rate of ~1' per second. The 2MASS data "tiles" are 6 deg. long in the declination direction and one camera frame (8.5')
wide. The camera field-of-view shifts by ~1/6 of a frame in declination from frame-to-frame. The camera images each point on the sky six times for a total integration time of 7.8 s, with sub-pixel "dithering", which improves the ultimate spatial resolution of the
final Atlas Images. The University of Massachusetts (UMass) is responsible for the overall management of the project, and for developing the infrared cameras and on-site computing systems at both facilities. The Infrared Processing and Analysis Center (IPAC) is responsible for all data processing through the Production Pipeline, and construction and distribution of the data products. The 2MASS project involves the participation of
members of the Science Team from several different institutions. The 2MASS project is funding by the National Aeronautics and Space Administration (NASA) and the National Science Foundation (NSF).

Acknowledging 2MASS in publications: Please include the following in any published material that makes use of the 2MASS data products:

"This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation."