Planets with Solid Surfaces:
* Mercury: Rocky, heavily cratered surface.
* Venus: Rocky, volcanic surface with a thick, toxic atmosphere.
* Earth: Rocky, diverse surface with oceans, continents, and mountains.
* Mars: Rocky, reddish surface with canyons, volcanoes, and polar ice caps.
Planets without Solid Surfaces (Gas Giants):
* Jupiter: Mostly hydrogen and helium gas with a possible small solid core.
* Saturn: Mostly hydrogen and helium gas with a possible small solid core.
* Uranus: Mostly hydrogen and helium gas with a possible small rocky core.
* Neptune: Mostly hydrogen and helium gas with a possible small rocky core.
Important Note:
* While these gas giants lack a true solid surface like the terrestrial planets, they do have atmospheric layers with increasing pressure and density as you descend.
* It's possible that at their core, they have solid rocky components, but we haven't directly observed them.
