Astronomers are scientists who study the universe. Many of them believe that the universe began about 15 billion years ago. They think that at first the universe was very, very small and made from completely different materials than it is today. Soon after it began, the universe started to spread out very rapidly. This growth is now called the Big Bang because it was so fast it was like an explosion.
The Big Bang
Before the Big Bang, the universe was the size of a pinhead. Then it expanded so rapidly that it was like an explosion. There was a great flash of light and intense heat of billions and billions degrees Celsius. There is nothing in the universe today that is as hot as that.
The universe began to clear up
After the Big Bang, the universe continued to spread out and cool slowly. At first, it seemed a hazy mass. As time passed, gases began to form and parts of the universe became clearer
Huge clouds formed
As the universe kept spreading out, gases came together to form huge clouds known as proto-galaxies. The proto-galaxies eventually gave birth to stars.
The universe today
Stars, gas and dust came together to form groups called galaxies. Galaxies can contain billions of stars. Today, the universe is made up of billions of galaxies.
THINGS TO DO
- Make your own universe by looking up the craft idea “solar system mobile” on www.mocomi.com
- Get to know more about our universe by looking up our ‘General Knowledge’ pages on www.mocomi.com
- Do some research on the Big Band experiment that is being conducted in Cern, Switzerland.
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