What Is a Planet?

Wiki Article

What Is a Planet?

A planet is a large, round object that orbits (moves around) a star—like our Sun. Planets do not produce their own light, but they can reflect the light of the star they orbit.

In our Solar System, there are 8 main planets, and they are divided into two groups:

The 8 Planets of the Solar System:

Inner (Terrestrial) Planets – Rocky and solid:

Mercury – Closest to the Sun, very hot and dry

Venus – Similar size to Earth but extremely hot

Earth – The only planet known to support life

Mars – Known as the Red Planet; has signs of ancient water

Outer (Gas and Ice Giants):

Jupiter – The largest planet; has a giant storm called the Great Red Spot

Saturn – Famous for its beautiful rings

Uranus – Spins on its side; icy and blue

Neptune – Very windy and farthest from the Sun

What Makes a Planet?

According to astronomers, a planet must:

* Orbit a star (like the Sun)

* Be large enough to be round in shape

* Clear its orbit of other debris

This is why Pluto is no longer considered a full planet—it’s now called a dwarf planet.

Beyond Our Solar System:

Scientists have discovered thousands of planets orbiting other stars. These are called exoplanets.

Some may even have the right conditions for life!

Fun Fact:

The word "planet" comes from the Greek word planets, meaning “wanderer,” because planets move across the night sky differently from stars.