10 Need-to-Know Things About the Sun:

1. The sun is a star. A star does not have a solid surface, but is a ball of gas (92.1 percent hydrogen (H₂) and 7.8 percent helium (He)) held together by its own gravity.
2. The sun is the center of our solar system and makes up 99.8% of the mass of the entire solar system.
3. If the sun were as tall as a typical front door, Earth would be about the size of a nickel.
4. Since the sun is not a solid body, different parts of the sun rotate at different rates. At the equator, the sun spins once about every 25 days, but at its poles the sun rotates once on its axis every 36 Earth days.
5. The solar atmosphere (a thin layer of gases) is where we see features such as sunspots and solar flares on the sun.
6. The sun is orbited by eight planets, at least five dwarf planets, tens of thousands of asteroids, and hundreds of thousands to three trillion comets and icy bodies.
7. The sun does not have any rings.
8. Spacecraft are constantly increasing our understanding of the sun -- from Genesis (which collected samples of the solar wind and returned the particles to Earth) to SOHO, STEREO, THEMIS, and many more, which are examining the sun's features, its interior and how it interacts with our planet. .
9. Without the sun's intense energy there would be no life on Earth.
10. The temperature at the sun's core is about 15 million degrees Celsius (27 million degrees Fahrenheit).