Scientists may have finally solved why the Moon's two sides look so different. Using samples collected from the lunar farside for the first time, researchers propose that uneven heating from Earth's gravitational pull drove enormous flows of ancient magma across the Moon's interior.
The new findings point to tidal heating as the key mechanism. As the early Moon orbited closer to Earth, gravitational stretching would have generated heat unevenly, concentrating magma activity on one side and leaving the other geologically distinct.
This is the first time farside samples have directly informed the debate, giving the team physical evidence to test a hypothesis that had previously relied on orbital data and models. The results offer a concrete explanation for the Moon's two-faced appearance, though further analysis of the samples will be needed to confirm the full story.