The Terrestrial Planets

Have you ever wondered why the planets closest to the Sun are composed of land and the outer planets are made out of gas? The four inner planets, or terrestrial planets, are all land-based planets that are composed of rock. The closest planet to the Sun is Mercury followed by Venus, Earth, and Mars. In this topic, you will explore the characteristics of the inner rocky planets. Some of these planets have thin gaseous atmospheres. In addition, you will learn a little about the geology of Earth's Moon.

Essential Questions

• What are the terrestrial planets?
• What are the characteristics of the terrestrial planets?
• What are the characteristics of Earth’s Moon?