Master of Science
Planetary Science and Exploration
Besides Earth, Titan is the only planetary body in our Solar System to currently have flowing liquid on its surface. Previous works note that dendritic and rectangular stream networks are present on a global scale on Titan, but do not map networks in the vicinity of Titan’s impact craters: Selk and Sinlap. The objective of this work is to understand how stream networks form adjacent to Titan’s impact craters. This information will inform future missions to Titan (i.e., Dragonfly) about the fluvial morphology of streams near their landing site. I conduct an analogue study with the stream networks at three terrestrial craters, Haughton, Siljan, and Popigai, to determine the effect of faults and target lithology on the morphology of their stream networks. My results suggest that Haughton’s streams are strongly controlled by faulting with a high percentage of networks classified as rectangular and that the crater’s geologic environment is the most analogous to craters on Titan. Preliminary mapping of Selk and Sinlap craters suggests that dendritic and rectangular networks are also present around impact craters on Titan.
Summary for Lay Audience
Titan, Saturn’s largest moon, and Earth are the only known planetary bodies in our Solar System to have liquid currently flowing on their surface. Although Earth’s fluids are made of water and Titan’s fluids are made of liquid methane and ethane, they form similar stream network patterns. These patterns tell us what mechanisms control a stream’s flow. Prior research demonstrated that rectangular and dendritic stream patterns are the most common morphologies seen on Titan. Rectangular patterns are associated with streams that follow faults or planes of weakness in the target rock and dendritic patterns refer to streams that flow through uniformly resistant rock with little to no regional slope. However, stream networks near Titan’s impact craters, Selk and Sinlap, have yet to be classified. NASA’s Dragonfly mission will be landing near Selk crater, and it is my objective to inform the Dragonfly team about what controls stream network formations at Titan’s impact craters. To do this, I conducted an analogue study with three craters on Earth: Haughton, Siljan, and Popigai. I sought to understand if stream formation is affected by local faulting and how the geology of the surrounding rock influences the networks’ patterns. Of the three craters, my results show that Haughton is the most analogous to Titan and has the most rectangular networks. I mapped one network each around Titan’s craters Selk and Sinlap, and found they followed a rectangular pattern and a dendritic pattern, respectively. These patterns are consistent with a previous study’s map of networks in the region where Selk and Sinlap are located. Higher resolution data from Dragonfly will better constrain the morphology of river networks around craters on Titan.
Duncan, Taylor M., "Terrestrial Craters as Analogues for Degraded Craters on Titan" (2023). Electronic Thesis and Dissertation Repository. 9636.