Recent research by NASA and the University of Arizona has revealed that a low-viscosity layer of goo exists between the Moon’s mantle and core, which moves in a manner similar to ocean tides due to the gravitational influence of the Earth and Sun.

The study, published in AGU Advances, marks the first measurement of the Moon’s gravitational changes caused by these tidal forces, supporting long-held theories about the Moon’s structure while raising new questions.

The scientists used data from NASA’s Gravity Recovery and Interior Laboratory (GRAIL) and Lunar Reconnaissance Orbiter to observe monthly and annual tidal movements, concluding that the presence of this semi-molten layer is necessary to explain their findings.

However, the research also highlights the mystery of what keeps this layer warm enough to remain in its malleable state, as reported by Futurism.

This discovery opens new avenues for understanding lunar geology and hints at deeper implications for the Moon’s thermal state and evolution.

Written by Emily Begley