The four planets that orbit closest to the Sun are best described as having rocky and terrestrial surfaces. Here's why:
1. Mercury: Mercury is the closest planet to the Sun and is rocky with a heavily cratered surface. It is a terrestrial planet, similar to Earth, Mars, and Venus.
2. Venus: Venus is the second planet from the Sun and has a rocky surface covered in dense clouds of sulfuric acid. It is also classified as a terrestrial planet due to its rocky composition.
3. Earth: Earth is the third planet from the Sun and is known for its diverse landscapes, including oceans, mountains, and deserts. It is a rocky, terrestrial planet that supports life.
4. Mars: Mars is the fourth planet from the Sun and is characterized by its red color due to iron oxide on its surface. It has a rocky terrain with features like valleys, volcanoes, and polar ice caps, making it another terrestrial planet.
Therefore, the four planets closest to the Sun—Mercury, Venus, Earth, and Mars—are all rocky and terrestrial in nature, with solid surfaces composed of rocks and metals rather than being mostly made up of gases, having rings like Saturn, or being entirely composed of water.
