The first four planets (Mercury, Venus, Earth and Mars) are called the Terrestrial Planets. A terrestrial planet or rocky planet is a planet that is composed of primarily silicate rocks or metals.

The next two planets (Jupiter and Saturn) are called the Gas Giants. This is due the their composition of Hydrogen and Helium. They are very large but much less dense than the earth.

The last two planets (Uranus and Neptune) are called the Ice Giants because of the extremely cold temperatures on these planets. This is due to the great distance they are from the sun.

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