In this section you’ll learn about the planet Earth. You’ll learn how far the Earth is from the Sun, what moons orbit Earth, how big Earth is, how long ago Earth formed and other facts about the planet Earth.

Earth Facts

In this section you’ll learn about the planet Jupiter. You’ll learn how far Jupiter is from the Sun, how big Jupiter is, how long ago Jupiter formed and other facts about the planet Jupiter.

Jupiter Facts

In this section you’ll learn about the planet Mars. You’ll learn how far Mars is from the Sun, how big Mars is, how long ago Mars formed and other facts about the planet Mars.

Mars Facts

In this section you’ll learn about the planet Mercury. You’ll learn how far Mercury is from the Sun, how big Mercury is, how long ago Mercury formed and other facts about the planet Mercury.

Mercury Facts

In this section you’ll learn about the planet Neptune. You’ll learn how far Neptune is from the Sun, how big Neptune is, how long ago Neptune formed and other facts about the planet Neptune.

Neptune Facts

In this section you’ll learn about Pluto. Even though the IAU reclassified Pluto in 2006, it holds a place in our hearts. Learn about Pluto’s history, how big it is and other facts about the dwarf planet Pluto.

Pluto Facts

In this section you’ll learn about the planet Saturn. You’ll learn how far Saturn is from the Sun, what moons orbit Saturn, how big Saturn is, how long ago Saturn formed and other facts about the planet Saturn.

Saturn Facts

In this section you’ll learn about the planet Uranus . You’ll learn how far Uranus is from the Sun, how big Uranus is, how long ago Uranus formed and other facts about the planet Uranus .

Uranus Facts

In this section you’ll learn about the planet Venus. You’ll learn how far Venus is from the Sun, how big Venus is, how long ago Venus formed and other facts about the planet Venus.

Venus Facts

 

Our Solar System formed about 4.6 billion years ago. There are currently eight known planets in our Solar System. These planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. There are 185 known moons (natural satellites) orbiting these planets. Jupiter has the most with 79 moons, and Earth has the least with one moon, Mercury and Venus have no known moons.

 

All eight planets orbit the Sun. The Sun is a main-sequence star in the center of our Solar System. All the planets orbit the Sun in a counterclockwise direction when viewed from the north pole of our Sun. The shortest orbital period is Mercury, it only takes about 88 Earth days to fully orbit the Sun. The longest orbital period is Neptune. It takes Neptune over 164 Earth years to complete an orbit around the Sun.

 

Between 1930 and 2006, Pluto was considered the ninth planet, but the International Astronomical Union in 2006 formally defined the term planet, effectively demoting Pluto to a dwarf planet.