Four global projections of the HST Titan data, separated in longitude by 90 degrees. Upper left: hemisphere facing Saturn. Upper right: leading hemisphere (brightest region). Lower left: the hemisphere which never faces Saturn. Lower right: trailing hemisphere. Not that these assignments assume that the rotation is synchronous. The imaging team says its data strongly support this assumption - a longer time baseline is needed for proof. The surface near the poles is never visible to an observer in Titan's equatorial plane because of the large optical path.
Credits: NASA, University of Arizona Lunar and Planetary Laboratory, STScI