Earth Science

The Solar System

Inner versus Outer Planets

Study Tip
Still looking for a clever way to remember the planets? Try My Very Elegant Moose Just Slurped Up Noodles.

The Inner Planets

  • Includes Mercury, Venus, Earth, and Mars.  
  • These are also called the terrestial planets.
  • They tend to spin slower on their axis.
  • They are usually composed of rock, such as nickel and iron.
  • These planets tend to have either one or no satellites.
Study Tip
Still looking for a clever way to remember the planets? Try My Very Elegant Moose Just Slurped Up Noodles.
The Inner Planets
The Outer Planets

The Outer Planets

  • Includes Jupiter, Saturn, and Neptune.
  • These are often referred to as the gas giants.
  • They take longer to orbit the Sun.
  • They are usually composed of more gases, such as hydrogen and helium.
  • These planets have numerous moons and rings. The rings are composed of dust and other small particles that encircle the planet on a thin plane.  
Concept Check
  • What main characteristics are different between inner and outer planets?
Concept Check
  • What main characteristics are different between inner and outer planets?