EXPLORING THE FORMATION OF DIONE’S WISPY TERRAINS

To date, no detailed fracture mapping of the wispy terrains of Saturn’s moon Dione have been completed in conjunction with a detailed characterization of the tectonic structures. Our analysis of the structures within Dione’s wispy terrains reveals tectonic features identified as scarps, twin scarps (likely graben), and troughs. Along with being less tectonically resurfaced than Enceladus, it is interesting that Dione’s tectonic structures are morphologically limited when compared with the wide diversity of tectonic structures on Enceladus’ surface. Using SatStressGUI, we model global-scale stress mechanisms including nonsynchronous rotation and diurnal tidal stresses at Dione’s surface to identify likely stress mechanisms that may have resulted in the fracture pattern across Dione’s wispy terrains. We present results from global stress modeling which suggests that a nonsynchronous rotation induced stress field may have been able to produce the observed fracture patterns in the wispy terrains. Nonsynchronous rotation has been suggested to have occurred, or is occurring on Europa and Enceladus, which infers the presence of global subsurface oceans. If the fracture pattern on Dione is attributed to nonsynchronous rotation, it would suggest that Dione has or had a global subsurface ocean.