These nine planets are grouped in many different ways. Two easy groupings are composition (what thay are made up of) and size.
COMPOSITION:
ROCKY PLANETS: (Mercury-Venus-Earth-Mars-Pluto)
The rocky planets are mostly made up of rock and metal . These planets are very heavy and move slowly. They also do not have rings and very few moons
GAS PLANETS : (Jupiter-Saturm-Uranus-Neptune)
The gas planets are mostly made up of gases (hydrogen and helium). These planets are light and move quickly. They have rings and lots of moons.