The Sun: The Basics

The sun is a star, a hot ball of glowing gases at the heart of our solar system. Its influence extends far beyond the orbits of distant Neptune and Pluto. Without the sun's intense energy and heat, there would be no life on Earth. And though it is special to us, there are billions of stars like our sun scattered across the Milky Way galaxy. If the sun were as tall as a typical front door, the Earth would be the size of a U.S. nickel. The temperature at the sun's core is about 27 million degrees Fahrenheit.

Average diameter: 864,000 miles, about 109 times the size of the Earth.

Rotation period at equator: About 27 days.

Rotation period at poles: About 36 days.

Surface temperature: 10,000 degrees Fahrenheit.

Composition: Hydrogen, helium.