You are here: Space > LET'S EXPLORE Space > How big is the Universe?

How big is the Universe?

The pattern of superclusters in the Universe. Billions of galaxies are gathered together in superclusters in the Universe. They...Read More >>The pattern of superclusters in the Universe. Billions of galaxies are gathered together in superclusters in the Universe. They make a net-like pattern. The areas in between the strands, called voids, are completely empty. You would have to travel billions of kilometres just to find a single atom!The Universe is everything we know. All matter, from the tiniest worm to the most gigantic star, belongs to the Universe. It even includes empty space. Nearly all matter in the Universe is contained in galaxies, giant star “cities”. About 100 billion galaxies are grouped together in giant clouds, called superclusters. These are spread around the Universe like a net. In the spaces in between there are vast empty spaces, known as voids.



The Andromeda Galaxy is a spiral galaxy like the Milky Way Galaxy—although it is thought to have twice the number of stars: 400...Read More >>The Andromeda Galaxy is a spiral galaxy like the Milky Way Galaxy—although it is thought to have twice the number of stars: 400 billion.

Galaxy clusters

The Universe's superclusters are made up of smaller clusters of galaxies. One of these, a cluster of 30 galaxies or so, is called the Local Group. It contains the Milky Way Galaxy, the vast spiral of stars to which our own star, the Sun, belongs.
The galaxies in this cluster are of several different types: spirals (like the Milky Way and the Andromeda Galaxy), barred spirals, ellipticals (shaped like ovals) and irregulars (no obvious shape).
The Andromeda Galaxy is a spiral galaxy like the Milky Way Galaxy—although it is thought to have twice the number of stars: 400...Read More >>The Andromeda Galaxy is a spiral galaxy like the Milky Way Galaxy—although it is thought to have twice the number of stars: 400 billion.

A diagram showing the Universe expanding during the big Bang, and the creation of galaxies.

Big Bang

The diameter of the Universe, the farthest distance it is possible for humans to see, is at least 93 billion light years across. It may actually stretch for more than 150 billion light years.

Q-files now has new sections specially written for younger readers. They are: Living world, Earth, Science, Human body, Prehistoric life, Space, History, Geography and Technology.


Find the answer