Terrestrial Planet Definition
A terrestrial planet is any planet in the universe that has earth-like composition, such as rocks, and other similar solid substances. For instance, Mars is a terrestrial planet in our solar system, whereas Jupiter is not. This is because modern geologists, astrophysicists, and astronomers understand Mars to contain solid formations correlative to earthly sedimentary rocks, igneous rocks, and metamorphic rocks. On the other hand, Jupiter is currently understood to be a gaseous stage planet with no core, mantel, or crust.
Terrestrial Planets in Our Solar System