A Mystery of Space: S T A R S- [About the Sun] U12

Thousands of years ago, people thought that the sun, and all the other planets, revolved around Earth. A man named Galileo proved that the Earth and the other planets revolved around the sun by watching sunspots, or dark spots on the sun.

picture of solar flare

The sun is a star like the North Star, and the stars in the Big Dipper. Because it is the closest star to earth, we know more about the sun than any other star. In fact, the closest star besides the sun is Alpha Centauri C (4.3 light-years from Earth).
We couldn't live without the sun, because it provides the heat we need to exist. Without the sun, Earth would be a cold, lifeless, ball of ice.