A new analysis of data from NASA’s Lunar Orbiter Laser Altimeter (LOLA), led by graduate student William Vaughan, shows that molten rock may have been present on the Moon more recently and for longer periods than previously thought. Differentiation — a settling out of rock layers as liquid rock cools — would require thousands of years and a fluid rock sea at least six miles deep.
The research shows that the impact event that formed the Orientale basin on the Moon’s western edge and far side produced a sea of melted rock 220 miles across and at least six miles deep. Similar seas of impact melt were probably present at various times in at least 30 other large impact basins on the Moon.
Read more of Kevin Stacey's story about moon melt.