centre of the Milky Way Galaxy
Central regions of the Milky Way Galaxy. The image on the left is in visible light, and the image on the right is in infrared; the marked difference between the two images shows how infrared radiation can penetrate galactic dust. The infrared image is part of the Two Micron All Sky Survey (2MASS), a survey of the entire sky in infrared light.
Two Micron All Sky Survey
astronomical survey
Also known as: 2MASS
Two Micron All Sky Survey (2MASS), astronomical survey conducted from 1997 to 2001 of the entire sky at near-infrared wavelengths. Two automated 1.3-metre (4.3-foot) telescopes were used. One was at Mount Hopkins, Arizona; the other was at the Cerro Tololo Inter-American Observatory in Chile. The observed wavelengths were 1.25, 1.65, and 2.17 microns (1 micron is 10−6 metre). The project was a collaboration between the University of Massachusetts at Amherst and the National Aeronautics and...