Jupiter, Saturn, Uranus, and Neptune have no solid surfaces. They are called the “gas giant” planets, but this term is misleading. The four largest planets in the solar system are mainly liquid worlds with thick, gaseous atmospheres. A rocket attempting to land on any of these planets would sink downward until it was crushed like a soda can by the weight of the overlying layers of that planet’s atmosphere.

It would be impossible to land a rocket on Jupiter, Saturn, Uranus, and Neptune because these planets don’t have any hard surfaces. Their atmospheres become thicker and thicker until they eventually change into liquid oceans. This drawing shows how an automatic spacecraft attached to a balloon might someday explore the upper atmosphere of Jupiter.