Terrestrial Planets

Terrestrial planets are a type of planet that is primarily composed of silicate rocks or metals. In our solar system, the terrestrial planets are Mercury, Venus, Earth, and Mars. These planets are also known as the inner planets because they are located closer to the Sun compared to the gas giants, which are the outer planets.

Characteristics of Terrestrial Planets:

1. Size and Density: Terrestrial planets are smaller in size compared to the gas giants and have higher densities. Their solid surfaces are made up of rocks and metals.
2. Atmosphere: They have relatively thin atmospheres compared to the gas giants. Venus has a thick, toxic atmosphere, while Mars has a very thin atmosphere.
3. Surface Features: Terrestrial planets have varied surface features including mountains, valleys, volcanoes, and impact craters. Earth is the only planet known to have active plate tectonics.
4. Temperature: They have a wide range of surface temperatures. Mercury has extreme temperature variations due to its lack of atmosphere, while Venus has a very hot surface due to its thick greenhouse effect.
5. Moons: Terrestrial planets have fewer moons compared to the gas giants. Earth has one large moon, while Mars has two small moons.

Comparison of Terrestrial Planets:

Study Guide:

Here are some key points to remember when studying terrestrial planets:

1. What are the characteristics of terrestrial planets?
2. How do the sizes and densities of terrestrial planets compare to gas giants?
3. Describe the atmospheres of terrestrial planets.
4. What are some common surface features found on terrestrial planets?
5. Compare the surface temperatures of Mercury, Venus, Earth, and Mars.
6. How many moons do terrestrial planets typically have?
7. Compare the diameters and surface temperatures of the terrestrial planets.

Understanding the unique characteristics of terrestrial planets is important for understanding planetary formation and the potential for habitability in other star systems.