The Universe and Objects Found in Space

The Universe includes all of space, as well as all the matter and energy within it. For example, the Universe contains stars, planets, satellites and billions of galaxies.

The universe is continually expanding, which means that it’s getting bigger over time. Let’s look at some examples of what we can find in the universe.


A galaxy is a collection of gas, dust and stars, all held together by gravity. Our galaxy is called the Milky Way; however, there are billions of other galaxies in the Universe.

  • The Milky Way galaxy contains billions of stars

A constellation is a group of stars that form particular patterns in the sky.

In space:

  • The distance between galaxies is millions of times more than the distance between stars in the galaxy
  • The distance between stars is millions of times more than the distance between the planets within the solar system

A light-year is a unit of astronomical distance used to describe distances in space. So, the distance that light travels in one year is a light year.

Objects Found in Space

There are many objects, other than planets, that we can find in space.


A comet is a ball of dust and ice that orbits the Sun.

Compared to planets, comets have a highly elliptical orbit.


In the solar system, asteroids orbit the Sun in elliptical orbits. Asteroids are mostly made of rock and metal and are typically found in the asteroid belt. Although they vary in size, asteroids are much smaller than planets.

When asteroids collide with each other in space, small pieces can break off. We call these pieces meteoroids and they can vary in size. If a meteoroid breaches Earth’s atmosphere, it becomes a meteor.


Meteors are balls of rock and dust. They typically burn as they enter the Earth’s atmosphere. They usually burn up in the mesosphere layer of Earth’s atmosphere.

Meteors can be seen in the sky as shooting stars. They rarely ever hit the Earth’s surface. But if they do, then we call them meteorites.


Satellites are objects that orbit planets. They can either be natural or artificial. The Earth has a natural satellite, which is the Moon.

The Moon

The Moon is a natural satellite which we can see in the night sky. It makes a complete orbit of the Earth every 27 days.

Earth is not the only planet with a moon; other planets have moons as well. For example, Uranus has over 25 moons.

Artificial satellites

Satellites launched into space by humans are known as artificial satellites. There are thousands of artificial satellites, including the International Space Station and communication satellites.