Number 86 (Story #3), June 26, 1992 by Phillip F. Schewe and Ben Stein PLUTO'S ATMOSPHERE may be dominated by nitrogen, according to recent observations by Tobias Owen of the University of Hawaii and his colleagues. Using the UK Infrared Telescope in Mauna Kea they detected spectral lines indicating for the first time the presence of nitrogen and carbon monoxide ice on Pluto's surface. Because these two substances, along with methane (previously discovered on Pluto), are some of the essential constituents of interstellar clouds, astronomers believe that studying the composition of Pluto may be useful in understanding the chemical processes which formed the solar system. (New Scientist, 20 June 1992.)