Question

Why are terrestrial planets closest to the Sun?

Answer 1

The terrestrial planets formed close to the Sun where temperatures were well suited for rock and metal to condense. The jovian planets formed outside what is called the frost line, where temperatures were low enough for ice condensation.

Answer 2

The Sun sent out energy and particles in a steady stream, called stellar winds. These winds proved so strong that they blew off mostthe gases of the four planets closest to the Sun, leaving them smaller, with only their rocks and metals intact. That's why they are called rocky, or terrestrial, planets.