University of Maryland study shows icy moons can retain oceans after collisions

New simulations led by the University of Maryland suggest that large icy moons in the outer solar system can retain or even deepen their subsurface oceans following cataclysmic collisions. The research, which included scientists from the Southwest Research Institute and the Weizmann Institute of Science, investigated whether massive impacts that shatter moons necessarily destroy their potential for liquid water.

By combining physics-based collision modeling with long-term thermal profiling over a 4.5-billion-year timeline, the team tested moons of two different scales: approximately 1,000km and 2,000km in diameter. The results indicated that while moons smaller than 1,000km are unlikely to maintain an ocean after a major impact, larger moons possess enough mass and thermal stability to reform and preserve their liquid water layers. In some instances, the process of reassembling after a collision can actually lead to a deeper ocean.