Not all planets are terrestrial. ... It's unclear what the dividing line is between a rocky planet and a terrestrial planet; some super-Earths may have a liquid surface, for example. In our solar system, gas giants are much bigger than terrestrial planets, and they have thick atmospheres full of hydrogen and helium.

Which planets do not have a surface?

Jovian planets include Jupiter, Saturn, Uranus, and Neptune. These planets have larger sizes and masses. Jovian planets do not have solid surfaces. They are sometimes called gas giants because they are large and made mostly of gases.

What planet does not have a flat surface?

Jupiter, Saturn, Uranus and Neptune

It actually has none to speak of. Jupiter, Saturn, Uranus and Neptune are all “gas giants.” As the nickname implies, these planets are made up of mixtures of hydrogen and helium and have no solid surfaces.