The sun, our closest star, is about 93 million miles away. It is composed of gases and measures 864,000 miles in diameter.
The sun is made up of layers. Each part differs in temperature with the hottest part of the sun located in the center. The center of the sun is called the core. Temperatures in the core reach 18 million degees Fahrenheit.
One important layer of the sun is called the photosphere. This is the visible surface of the sun. The temperature here is 10,000 degrees Fahrenheit. On the surface of the sun, there are sunspots. These sunspots are slightly cooler and appear dark in color. Sunspots are believed to be about 8,000 degrees Fahrenheit.
Another major component of the sun is the chromosphere. This layer is directly above the surface of the sun. The temperatures in this area vary greatly. Just above the surface of the sun, temperatures stay at approximately 7,200 degrees. However, as one moves out toward the edge of the chromosphere, the temperature increases dramatically. Beyond this region lies the corona (a thin hot plasma that becomes visible during the total solar eclipse). Here, temperatures can reach millions of degrees!