Planet Earth is the third planet from the Sun in our solar system. It is the only known planet that supports life, thanks to its atmosphere, which contains oxygen and protects living organisms from harmful solar radiation. Earth has diverse environments, including oceans, mountains, forests, and deserts, which host a wide variety of plants and animals. The planet has a diameter of about 12,742 kilometers and is primarily composed of rock and metal. Earth orbits the Sun at an average distance of approximately 149.6 million kilometers. Its rotation on its axis creates day and night, while its orbit around the Sun results in the changing seasons.