Enormous telescopes like the Very Large Telescope in Chile--the subject of last month's cover story in Discover--collect so much light that astronomers can afford to throw some away. These pictures, all of galaxy NGC 1232, about 100 million light-years from Earth in the constellation Eridanus, are the products of such squandered photons.
The photograph above at right was created from two digital images of the galaxy, one in ultraviolet and one in blue light. Astronomers from a consortium of German universities subtracted the blue light from the ultraviolet, resulting in a portrait that highlights star formation regions.
The same principle produced the galactic view at left. In this case, an infrared image was subtracted from a visible-light photograph to emphasize dark, dusty lanes spiraling into the galactic center.