Ten years after NASA’s New Horizons spacecraft revealed Pluto’s astonishingly varied surface, towering water-ice mountains, flowing nitrogen glaciers, and the vast heart-shaped Sputnik Planitia, scientists have found something else in the data: landslides.
Six large-scale landslides have been identified for the first time on the dwarf planet, all located along the inner rims of three impact craters on the western edge of Sputnik Planitia. The findings, published in Icarus by an international team led by Marco Emanuele Discenza, reveal that gravitational mass wasting is a geologically active (or recently active) process on Pluto, and that the resulting debris flows are among the most mobile in the solar system.
“Pluto continues to surprise us,” said Maria Teresa Brunetti, a physicist at Italy’s National Research Council (CNR) in Perugia and a co-author on the study. “These landslides tell us that the dwarf planet’s surface is more dynamic than we expected, even at these extreme temperatures.”
Extreme mobility in low gravity
The landslides were detected in images from New Horizons’ LORRI (Long-Range Reconnaissance Imager) camera, paired with elevation maps constructed from the flyby’s stereo imaging. At approximately 300 meters per pixel resolution, the team identified the classic geomorphological signatures of landslides: crescent-shaped headscarps at crater rim tops, displaced blocks of ice, and lobate debris aprons spreading across crater floors.
The six slides range in drop height from 1.5 to 2.2 km (0.9-1.4 miles) and in runout length from 10.1 to 14.5 km (6.3-9.0 miles). The largest covers approximately 130 square km (50 square miles), roughly twice the area of Manhattan.
What makes the Pluto landslides remarkable is their mobility ratio, the distance traveled relative to the vertical drop. At Pluto’s surface gravity of just 0.062 g (one-sixteenth of Earth’s), the icy rubble behaves almost like a fluidized flow, sliding far farther than a comparable Earth landslide for the same drop height.
“This is a combination of very low gravity and low-friction icy rubble,” said Goro Komatsu of the Universita d’Annunzio in Pescara, Italy, a co-author. “The debris effectively floats over the surface.”
What triggers a landslide on Pluto?
For at least one of the slides, in Coughlin crater, the trigger appears clear: a smaller impact that formed a secondary crater on the crater rim destabilized the wall, setting off the cascade. For the remaining five, the cause is less certain.
The team points to thermal stresses as a likely mechanism. Pluto’s surface ices, nitrogen, methane, carbon monoxide and water ice, undergo cycles of sublimation and recondensation driven by temperature fluctuations across Pluto’s highly elliptical 248-year orbit. Over geological timescales, these cycles may create enough stress to trigger slope failure.
“The trigger for Pluto’s landslides is not yet clear for most of these features,” the authors note, and they call for future orbital reconnaissance to resolve the question.
Implications for Pluto’s geological activity
The discovery confirms that Pluto remains geologically active, with gravitational slope processes shaping its surface even at cryogenic temperatures averaging around minus 230 degrees Celsius (minus 382 degrees Fahrenheit). It adds Pluto to the short list of solar system bodies, Earth, Mars, Venus and a handful of icy moons, where landslides have been documented.
The study also opens questions for future missions. New Horizons imaged only one hemisphere during its 2015 flyby. A proposed Pluto orbiter, still a concept, would provide the resolution and global coverage needed to determine whether these landslides are rare events or part of a planet-wide process.
Sources
Discenza ME, Brunetti MT, Minnillo M, Grundy W, Komatsu G. “First geomorphological evidence of landslides on Pluto.” Icarus 459, 117210 (2026). DOI: 10.1016/j.icarus.2026.117210
Space.com. “Astronomers discover landslides on Pluto large enough to bury entire cities on Earth.” July 2026. https://www.space.com/astronomy/pluto/astronomers-discover-landslides-on-pluto-large-enough-to-bury-entire-cities-on-earth