NASA’s GRAIL mission, launched in 2011, has helped solve the puzzle of the Moon’s asymmetrical appearance.
Using dual satellites Ebb and Flow, the mission mapped the Moon’s gravity field, revealing that the nearside has a thinner crust, higher heat levels, and was more volcanically active due to heat-producing elements like thorium and titanium.
In contrast, the farside has a thicker crust and fewer lava plains.
These differences are due to gravitational asymmetry and tidal flexing, caused by Earth’s gravitational pull—a key insight into the Moon’s internal structure and thermal evolution.
