ON 3 July 1989 the bright K giant star 28 Sgr was occulted by Saturn's largest moon, Titan. This event, which was predicted by Wasserman1, offered a unique opportunity to probe Titan's extensive nitrogen-rich atmosphere in an altitude range not investigated by the Voyager 1 spacecraft2,3. Our group observed the occultation from three stations in the Mediterranean area, and here we examine the data set. We derive average mesospheric temperatures of ∼180 K, with evidence for lateral and vertical atmospheric inhomogeneities on scales ranging from ∼10-1,000 km. Our results are consistent with published models4of Titan's mesosphere.