Titan may have an icy surface Apr 25, 2003 The surface of Titan,
Saturn’s largest moon, may contain frozen water. Caitlin
Griffith at the University of Arizona and colleagues at the
Institute for Astronomy in Honolulu, the Gemini Observatory and
the Université Pierre et Marie Curie measured the infrared
spectrum of the moon’s surface and detected the tell-tale
characteristics of water ice. This result may overturn the
hypothesis that Titan’s surface is completely covered by a thick
layer of organic liquids and solids (C A Griffith et al. 2003
Science 300 628). The atmosphere of Titan is made up of a thick
haze, about 800 metres deep, of methane, nitrogen and carbon
dioxide. This layer obscures the surface and makes it difficult
to detect what lies below. Previous studies focused on a small
range of wavelengths but spectral peaks that are characteristic
of surface compounds only show up at a larger range of
wavelengths. It is known from the Voyager mission that the
atmosphere of Titan becomes more transparent