What is the Difference Between Inner and Outer Planets?

3 minute read
Difference Between Inner and Outer Planets

The main difference between the inner and outer planets lies in their composition, size, and orbital characteristics. As you know there are a total of 8 planets in the solar system. Out of these 8, four are outer planets and the remaining four are inner planets. 

To completely understand our solar system, we need to understand the major difference between Inner and Outer planets. Here in this blog, we have discussed all the major differences between the Inner and Outer planets. Keep reading for more.

What are Inner Planets?

The inner planets are known as terrestrial planets, which are the four planets closest to the Sun. These planets are Mercury, Venus, Earth, and Mars. These planets are made of composed of silicate rocks and metals. 

Inner planets are relatively small compared to their outer counterparts. Inner planets have shorter orbital periods 

What are Outer Planets?

The outer planets, also known as the gas giants, are the four planets farthest from the Sun. These planets are Jupiter, Saturn, Uranus, and Neptune. 

The main components of these planets are hydrogen and helium. The deep atmosphere of these planets transits into liquid and then finally converts into metallic hydrogen.

What is the Difference Between the Inner and Outer Planets?

Many factors can differentiate between the Inner and Outer planets. Here is the tabular representation to understand the main difference:Here we have listed the main differences between the inner and outer planets:

Factors Inner Planets Outer Planets 
CompositionComposed of solid, rocky materials such as silicate rocks and metalsComposed of hydrogen and helium, with rocky cores
SizeRelatively smallMuch larger
DensityHigher density Lower average density 
SurfaceSolid surfacesNo solid surface, just thick atmospheres
ExamplesMercury, Venus, Earth, MarsJupiter, Saturn, Uranus, Neptune
OrbitsShorter orbital periods Longer orbital periods
Orbit StructureOrbits are generally more circularOrbits are more eccentric, elongated and tilted

Also Read: What is the Difference Between Device and Machine? Complete Details

Similarities Between Inner and Outer Planets

There are just a few general similarities. Overall, the differences between inner and outer planets are much more significant.Here are the similarities between inner and outer planets:

  • Both inner (Mercury, Venus, Earth, Mars) and outer planets (Jupiter, Saturn, Uranus, Neptune) are members of our solar system, orbiting the sun.
  • All planets, inner and outer, have a roughly spherical shape due to gravity pulling their mass inwards.
  • While not all planets have them, both inner and outer planets can have moons orbiting them.


What is the difference between Inner and outer planets in density?

According to the reports, the density of inner planets is higher in comparison to outer planets.

What are outer planets?

There are 4 outer planets in the solar system. The outer planets have longer orbits, faster spins, a composition of gases and liquids, numerous moons, and rings.

What are inner planets?

As for outer planets, there are 4 inner planets in the system. They have shorter orbits, slower spin, no rings, and they are made of rock and metal. 

What is the Difference Between
Standard Deviation and Standard Error?
What is the Difference Between
Volume and Area
What is the 2-3-5-7 Study Method?
Complete Guide to Beat the Exams
What is the Difference Between Regulated and Unregulated Power Supply?
What is the Difference Between Torque and Force?What is the Difference Between
Active and Reactive Power?

This was all about the “Difference Between Inner and Outer Planets”.  For more such informative blogs, check out our Study Material Section, you can learn more about us by visiting our  Indian exams page.

Leave a Reply

Required fields are marked *