Analysis of Transient Fog Features on Titan

Abstract

Saturn’s moon Titan is the only known solar system body other than Earth with an active hydrologic cycle, based on methane instead of water. To better characterize this environment, this thesis examines transient low-altitude methane clouds (hereafter referred to as fogs) that have been observed near Titan’s surface in data from the Visual and Infrared Mapping Spectrometer (VIMS) onboard the Cassini mission. We compile a data set of 19 fog features, expanded from previous studies, and investigate a range of factors that could influence fog formation. We find a tendency for fogs to be observed at high latitudes and primarily in the north, in agreement with modeling of Titan’s humidity. They also show a potential correlation to the locations of methane lakes, with several features that appear to trace shorelines. They may also be preferentially observed in seasons with higher insolation. These results can guide future modeling efforts, as well as continued data collection, to further constrain fog formation mechanisms.