Number 82 (Story #2), June 2, 1992 by Phillip F. Schewe and Ben Stein THE EXTREME ULTRAVIOLET EXPLORER (EUVE) , a satellite expected to be launched this month, will map the sky at wavelengths between 100 and 900 angstroms, an energy range important for studying stellar atmospheres and white dwarfs. The EUV band is hard to observe, however, since it is largely absorbed by clouds of interstellar hydrogen atoms. This limits effective viewing to a region of space out to about 300 light years, a volume that is, fortunately, relatively free of hydrogen. Rosat, the German satellite, has also been mapping the sky at EUV (and at soft x-ray) wavelengths, but does not have the EUVE's ability to study the spectra of individual sources. (Science News, 23 May 1992.)