Comets and Asteroids

What Are Comets?

Comets are icy rocks that travel around the Sun.
When a comet gets close to the Sun, the heat melts its ice.
The melted ice turns into gas and dust, making a bright tail that points away from the Sun.
Comets can be seen from Earth when they shine in the night sky.

What Are Asteroids?

Asteroids are rocky pieces that orbit the Sun, mostly between Mars and Jupiter.
They do not have ice, so they do not have tails.
Some asteroids are big, like mountains, while others are tiny like pebbles.
Scientists study asteroids to learn about the early Solar System.

How They Move

Both comets and asteroids travel in paths called orbits.
The Sun’s gravity pulls them around, keeping them in space.
Sometimes a comet’s tail can point in different directions because the wind from the Sun pushes the gas and dust.
Asteroids stay steady on their paths unless something, like another planet, nudges them.