What is at the center of the Solar System?
What is a planet?
The Sun is 93 million miles away. How can we feel its warmth?
Our home in Space
What are the kinds of objects that make up the Solar System?
The Solar System is our home in space.
The Sun in the center of the Solar System. The Sun is a star. On some days, sunshine feels hot. But the sun is almost 93 million miles away!
Other objects travel around the Sun in paths called orbits. The biggest of these objects are planets. A planet is a large, ball-shaped object that travels around a star.
Our Solar System has eight planets. Four of these planets are in the inner Solar System, closer to the Sun. These planets are Mercury, Venus, Earth, and Mars. They are all rocky planets.
The other four planets are in the outer Solar System. These planets are Jupiter, Saturn, Uranus, and Neptune. They are giant balls of gases.
Many other objects move around the Sun, too. Some of these objects are like planets, but they are smaller than the eight planets. They are called dwarf planets. Pluto is one of these dwarf planets.
Other objects that move around the Sun are asteroids and comets.
Six of the planets have at least one moon. Mercury and Venus have no moons.