The Planets and Space Exploration

The four planets at the center of the solar system are solid, rocky bodies like the Earth. They include Mercury, Venus, and Mars. Jupiter, Saturn, Uranus, and Neptune are all made mostly of gas and are called giant planets because they are so large compared to Earth.

Their are several dwarf planets that are much smaller than Earth. Pluto, Haumea, Eris, Makemake, and the asteroid Ceres are all dwarf planets.

Unmanned spacecraft have traveled to all the planets in the solar system and taken pictures of the planets and many of their moons. They have also taken measurements that tell us what the planets are like inside.

Big, Bigger, Biggest

A Solar System Model Builders Guide

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Dwarf Planets

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Pluto

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Eris - a dwarf planet

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Makemake: a Dwarf Planet

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The Solar System

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The Beginning of the Solar System

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