Chaos terrains are geologically young and extensively disrupted surface features of Europa, thought to be an expression of the subsurface ocean interacting with the surface. The most prominent examples of this terrain on Europa are Conamara Chaos, and Thera and Thrace Maculae, all prime targets for the upcoming JUICE and Europa Clipper missions to assess the astrobiological potential of Europa. Of the three features, Thrace Macula is currently the least studied and understood. It intersects both Agenor Linea to the north and Libya Linea to the south, two important regional‐scale bands whose interaction with Thrace is yet to be fully unraveled, especially in terms of their relative ages of emplacement and activity. Using Galileo Solid State Imager data and Digital Terrain Models, we conducted detailed structural mapping and terrain analysis to develop a novel hypothesis on the mechanisms involved in the study area. We find that Thrace Macula is bordered along most sides by preexisting strike‐slip faults that have constrained its emplacement and areal distribution. We determine a sequence of events in the area involving the formation of Agenor Linea, followed by that of Libya Linea first and Thrace Macula later, and ultimately by strike‐slip tectonic activity likely driven by Libya Linea, that displaced a portion of Thrace Macula. Therefore, Thrace's subsurface material, uprising along faults postdating its formation, represents the freshest possible that could be sampled by future spacecraft in this region, a major consideration for the upcoming Europa Clipper mission.
N2 - Plain Language Summary: Europa, an icy moon of Jupiter with a large subterranean water reservoir, has unique surface features known as chaos terrains, believed to result from interactions between its subsurface ocean and surface. Of these terrains, Conamara Chaos and Thera and Thrace Maculae are prime targets for upcoming missions to investigate the astrobiological potential of Europa. However, Thrace Macula, which is situated between Agenor Linea to the north and Libya Linea to the south (two large‐scale bands, linear geological features), remains poorly understood. In this study, we used detailed mapping of faults and lineaments, together with topographical analysis, to propose a new hypothesis for the formation and evolution of Thrace Macula. Our findings suggest that preexisting tectonic faults constrained its emplacement and distribution, while a sequence of events starting with the formation of Agenor Linea, followed by Libya Linea first and Thrace Macula later, culminated in strike‐slip tectonic activity likely driven by Libya Linea that displaced a portion of Thrace Macula. These results imply that future spacecraft could sample Thrace's subsurface material uplifting along faults postdating its formation, the freshest available in this region. This research sheds light on Europa's regional history and its astrobiological potential. N2 - Key Points:We conducted structural analysis on Thrace Macula, a chaotic terrain on Europa, based on imaging and newly processed topographic data
We found that preexisting strike‐slip faults border Thrace Macula and have constrained its emplacement and areal distribution
We provide insights into the history of Thrace and identify it as a prime location for future missions to sample fresh subsurface material