NASA’s Dawn spacecraft provided insights into the giant asteroid Vesta, notably capturing images that reveal the presence of unusual gullies alongside its heavily cratered surface. Previously thought to be formed by dry debris flows, recent studies suggest these gullies may result from brief flows of briny water triggered by meteoroid impacts. Research conducted at NASA’s Jet Propulsion Laboratory (JPL) explored how sodium chloride can stabilize salty water, allowing it to flow longer before freezing. Experiments mimicked Vesta’s conditions and found that while pure water freezes instantly in a vacuum, briny solutions remain liquid for at least an hour—sufficient time to carve surface features similar to those on Earth.
The implications of these findings extend beyond Vesta, potentially providing understanding into similar processes on other celestial bodies like Ceres. This research underscores the role of liquid brines in shaping landscapes on airless worlds, suggesting that even in the harshest conditions, liquid water can play a crucial role in geological activity. The study emphasizes the importance of lab experiments in extrapolating geological processes on extraterrestrial surfaces, contributing to our understanding of planetary evolution within our solar system.
