* Terrestrial Composition: All four are primarily composed of rock and metal, unlike the gas giants.
* Smaller Size and Mass: Compared to the outer planets, they are significantly smaller and less massive.
* Solid Surface: They all have a solid surface, unlike the gas giants which have a gaseous atmosphere surrounding a solid core.
* Fewer Moons: They have few or no moons, unlike the gas giants with their extensive moon systems.
* Closer to the Sun: Naturally, they are located closer to the Sun than the outer planets.
* Shorter Orbital Periods: Due to their proximity to the Sun, they have shorter orbital periods (the time it takes to orbit the Sun).
* Less Dense: They are less dense than the outer planets, largely due to their rocky composition.
While these similarities are significant, each inner planet has its own unique characteristics and features, making them distinct from one another.
