Geomorphological Evidence of Fluid Seepage in Pit Complex Formation, Pioneer Terra, Pluto

Abstract Pluto exhibits widespread pit complexes thought to originate from endogenic processes, possibly involving gaseous effusions from the subsurface, though their formation mechanism remains elusive. Here, we analyze the geomorphology of 150 pits and surrounding features using New Horizons imagery. The pit complex in Pioneer Terra features tectonic lineations and shares distinct morphologies as evidenced by their distribution, cross‐sectional, and planform shapes. Drawing parallels with terrestrial analogs, we propose that these pits are potential candidates for fluid migration and seepage events, formed similarly to gas pockmarks in areas with seepage activity on Earth. Our findings imply the presence of volatile reservoirs in Pluto's subsurface, that may episodically release volatiles affecting local landscapes and contributing to the atmosphere. We offer a conceptual model for fluid migration and seepage in the formation of pits in this region, which may also occur across other icy worlds. Future investigations of fluid source and plumbing systems, together with our geomorphic analysis, would further elucidate processes and properties in Pluto's subsurface, thereby advancing our understanding of Pluto's broader geophysical and atmospheric evolution.