Why are some planets rocky while others are balls of gas?

A planet’s makeup depends largely on its place in the solar system. The four ‘’inner planets’’ formed from the debris that orbited closer to the sun. The ‘’outer planets’’ developed well beyond the orbit of Mars from gases and ice. The eight planets (and numerous dwarf planets) in our solar system come in three flavors…

Terrestrial planets: These smaller inner planets – which include Mercury, Venus, Earth, and Mars  – are made of solid matter: rocks and metals.

Gas giants: Jupiter and Saturn are titanic balls of hydrogen and helium. Some astronomers consider them failed stars.

Ice giants: The far-flung worlds of Uranus and Neptune are gas giants like Jupiter and Saturn, but astronomers also call them ice giants because their atmosphere is composed mostly of ‘’icy’’ water, ammonia, and methane.


Picture Credit : Google