Final answer:
The four planets closest to the Sun - Mercury, Venus, Earth, and Mars - are called terrestrial planets. These planets are relatively small and composed primarily of rock and metal.
Step-by-step explanation:
The four planets closest to the Sun - Mercury, Venus, Earth, and Mars - are called terrestrial planets. These planets are relatively small and composed primarily of rock and metal. They have solid surfaces with features such as craters, mountains, and volcanoes.