* Earth: Our home planet has a solid, rocky crust.
* Mars: Mars has a thin crust, but it is solid.
* Mercury: Mercury has a very thin crust, but it is also solid.
* Venus: Venus has a solid, but very thick crust.
While Jupiter, Saturn, Uranus, and Neptune are gas giants, they do not have a solid surface like the terrestrial planets above. They have a core, but it's surrounded by layers of gas and liquid.
