Aristarchus was a very clever man who lived a long time ago in Ancient Greece. He had a really cool idea about how the Earth, Sun, and Moon move around each other.
He thought the Sun was the center of the universe and everything else moved around it. This was different from what most people believed at the time, which was that the Earth was the center of everything and everything else moved around it.
To help explain his idea to other people, Aristarchus came up with special symbols. These symbols helped people understand how the Earth, Sun, and Moon move around each other.
For example, he used a symbol that looks like a circle with a dot in the middle to represent the Sun. This meant that the Sun was the center of everything.
He also used a symbol that looks like a half moon to represent the Moon. This meant that the Moon moves around the Earth.
And he used another symbol that looks like a small circle to represent the Earth. This meant that the Earth moves around the Sun.
These symbols helped people understand Aristarchus's really cool idea about how the Earth, Sun, and Moon move around each other.