NASA's Dawn spacecraft, which orbited asteroid Vesta in 2012, captured images of enigmatic gullies on the asteroid's surface, prompting scientists to investigate their origins. A recent study published in the Planetary Science Journal explores the possibility that these gullies were formed by brief liquid flows involving briny water. Researchers at NASA's Jet Propulsion Laboratory (JPL) simulated conditions similar to Vesta's surface using the Dirty Under-vacuum Simulation Testbed for Icy Environments (DUSTIE). The experiments revealed that while pure water would freeze almost instantly in the vacuum of space, briny solutions could remain liquid for up to an hour—enough time to carve surface features.

The study suggests that impacts from meteoroids could have exposed subsurface brine, triggering temporary flows that shaped Vesta's surface before freezing. These findings have implications beyond Vesta, aligning with similar processes observed on Mars and Europa, and add new layers to our understanding of geologic activity on airless worlds. This research also builds on discoveries made during the Dawn mission, which identified brines on Ceres in the asteroid belt. While frozen brine on Vesta has yet to be confirmed, the study opens up exciting possibilities for understanding planetary geology on icy and airless bodies.