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LESSON 3 · Grand Tour of the Solar System

The Habitable Partnership

The Earth-Moon system shows how multiple factors can support life over billions of years. Earth's magnetic field, plate tectonics, liquid water, atmosphere, and large Moon all influence long-term stability.

Remove one factor and the planet changes, sometimes dramatically. But habitability is not a simple checklist: scientists still debate how necessary each factor is, especially the Moon's role in stabilizing Earth's tilt.