Earth is the third planet from the Sun and the only known celestial body to support life. It has a diameter of approximately 12,742 kilometers and features a dynamic environment with vast oceans, a protective atmosphere rich in nitrogen and oxygen, and diverse ecosystems. Earth's layered structure includes a solid crust, molten mantle, and a metallic core that generates a magnetic field,

The Moon, Earth's only natural satellite, is about one-quarter Earth's size (3,474 km in diameter) and orbits at an average distance of 384,400 km. Formed roughly 4.5 billion years ago from debris after a Mars-sized body collided with Earth (Giant Impact Hypothesis), its surface is marked by craters, mountains, and dark basaltic plains called maria. temperature swings and preserves a record of ancient impacts. The Moon's gravitational pull creates Earth’s tides, and its synchronous rotation means only one face is visible from Earth. Human missions, like Apollo 11,