Astronomers have completed the most thorough high-resolution digital survey of the heavens to date and released its 5 million images on the Internet.
The map of the sky took four years of observations and $40 million to complete. It contains an estimated 500 million celestial objects, mostly stars but also galaxies, asteroids and comets. The project's twin telescopes, in Arizona and Chile, mapped the sky in the infrared part of the electromagnetic spectrum. The University of Massachusetts Amherst led the Two Micron All-Sky Survey.