Life on Earth would not be possible without the Moon; it keeps our planet's axis of rotation stable, which controls seasons and regulates our climate. However, there has been considerable debate over how the Moon was formed. The popular hypothesis contends that the Moon was formed by a Mars-sized body colliding with Earth's upper crust which is poor in metals. But new research suggests the Moon's subsurface is more metal-rich than previously thought, providing new insights that could challenge our understanding of that process.