All-sky survey makes Internet debut

Last month, an atlas of some 5 million images from the celestial map known as the Two Micron All-Sky Survey (2MASS) became available online (see It’s the most detailed high-resolution survey of the entire sky so far (SN: 2/23/02, p. 122: The Milky Way’s Middle).

SEEING RED. Sky-survey image of the spiral galaxy NGC 891, seen edge-on in the infrared. 2MASS

Researchers conducted the survey at infrared wavelengths, using identical 1.3-meter telescopes in the northern and southern hemispheres. Because infrared light emitted by stars and galaxies penetrates dust more easily than their visible light does, infrared telescopes are more likely to reveal objects hidden behind dust.

The images add to the storehouse of astronomical data already online, which scientists hope will become part of a national virtual observatory. With such a resource, which includes analytical tools for finding patterns within the raw data, astronomers could make discoveries without leaving their offices.

For example, notes Michael Skrutskie of the University of Virginia in Charlottesville, with 2MASS, “we can, in effect, step outside our galaxy and see it in detail, as it would appear from above.” The survey, he adds, also enables astronomers to discern details in the distribution of galaxies outside the Milky Way.


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