What is the universe?
The universe is everything that exists. The universe is also called the cosmos and the study of the universe is called cosmology.
Everything you see and touch on Earth is part of the universe. All the planets and stars in the sky, the entire solar system, milky way and galaxies are all part of the universe. All matter and all energy and time itself are all contained in the universe. That’s too crazy to even imagine!
Scientists use telescopes and astronauts go on space expeditions to try and discover more about the universe, but there is still so much we do not know.
Facts about the universe
- The universe has no centre.
- The universe seems to be cooling and may eventually freeze.
- Big, empty spaces in the universe are called voids.
- Some scientists today think that the universe is flat.
How big is the universe?
The universe is bigger than a billion Earth’s all put together! It’s so big that we can’t even see it. It takes light 8 minutes to travel from the Sun to the Earth. Even astronauts that travel to space have only seen a tiny amount of the universe.
The universe is about 93 billion light-years wide (light-years are a form of space measurement).
The universe is expanding
The universe is always growing. It gets bigger every second so you can never reach the edge of the universe. Some scientists think that it may stop expanding and start to contract (get smaller).