Polygonal impact craters on Dione: Evidence for tectonic structures outside the wispy terrain

We tested for PICs using crater rim azimuth data collected from randomly distributed study locations throughout the non-wispy terrain. From these data, we identified widespread PICs in this terrain, which supports the hypothesis that subtle fractures are also present. Analysis of the PIC azimuth data yield a pattern for these inferred fractures across Dione's surface that is consistent with the hypothesized global deformation that would result from a combination of satellite despinning and volume expansion. Our results provide evidence for these previously hypothesized events in Dione's history and demonstrate that mapping PICs and their azimuths is a useful tool for investigating subtle fractures on Solar System bodies.