1. THESUNISVERYOLD. The Sun is one of 100 billion stars in our Milky Way galaxy. Scientists estimate that the Sun is about 4.5 billion years old.
2. THESUNISNOTSOLID. The Sun is composed of plasma, a material made from electrically charged gas atoms. It is about 75 percent hydrogen and about 25 percent helium. The remaining traces are tiny amounts of metals.
3. THESUNISREALLYFARAWAY. The Sun is about 93 million miles away from Earth.
4. THESUNISHUGE. The Sun is about 865,000 miles in diameter — that’s as wide as 109 Earths placed side by side! About 1 million Earths would fit inside the Sun.
5. THESUNMOVESVER-R-R-Y SLOWLY. The Sun is the center of our solar system, but it doesn’t stay in one place. It orbits around the center of our Milky Way galaxy, which is about 28,000 light-years away. It takes the Sun about 226 million years to go around the galaxy once!
6. SECTIONSOFTHESUNSPINATDIFFERENTSPEEDS. The Sun rotates on its axis in the same direction as Earth (counterclockwise, when looking down from the north pole). Because the Sun is gaseous, different sections rotate at different speeds. At the surface, the area around the equator rotates once about every 25 days. The Sun’s north and south poles rotate more slowly. It can take those areas more than 30 days to complete one rotation.
7. THESUNHAS A LOTOFPULL. The Sun makes up more than 99 percent of the total mass of the solar system. Because it is so massive, the Sun exerts a lot of gravity, or pull, on the planets — enough to cause them to orbit around it. The Sun’s gravity is about 27.9 times that of Earth, and, in a small way, it helps to control the tides on Earth.
8. THESUNIS A BALLOFENERGY. The Sun’s core is under a lot of pressure. Because of this, hydrogen atoms are constantly colliding with each other at great speeds, fusing together to form helium, and releasing energy. Lots of these collisions occur, creating an enormous amount of energy. As a matter of fact, in just 1 second, the Sun produces about 118 trillion times as much energy as the United States used in the year 2003!
9. THESUNISHOT. The Sun’s temperature varies over time and through its eight layers. The hottest part of the Sun is the core, at 28,080,000 degrees F, on average.
10. THESUNHASSPOTS. When the Sun’s magnetic field pokes through the surface, it prevents the heat rising inside from coming through. As a result, the Sun’s surface at these areas is cooler and darker than its surroundings, although still very bright. These dark areas are called sunspots.