Last February, astronauts from the space shuttle Discovery replaced a set of aging instruments on the Hubble Space Telescope with two new instruments designed to look at the colors of the universe in an entirely new way.
The first of the two, the Near Infrared Camera and Multi-Object Spectrometer (nicmos), is a camera that sees shades of infrared light the way normal cameras see colors. The result is an instrument that can see inside dust clouds—dust clouds near the center of the galaxy, for instance, where later in the year nicmos discovered perhaps the most massive star ever observed (see article opposite).
The other new instrument, the Space Telescope Imaging Spectrograph (stis), takes light from an object and separates it into discrete wavelengths—but instead of the colored lines that emerge from an old-fashioned spectrograph, stis creates a spectrum of images, one at each wavelength.
The images seem bizarre at first, but if you know how to look at them, they contain much more information than ordinary spectra or the familiar Hubble pictures, which combine light from just a couple of wavelengths. You can use this information to work out the chemistry, velocity, and density of the object, says Bruce Woodgate, the nasa astronomer in charge of the instrument. And you can do it all at once and get the information you need 40 times faster than with a normal spectrograph.
