One of the most important features of every day life is the sun. It rises and sets, and we use it to fix our daily routine. Without it we would not receive the light and heat that provides us with energy. This star, our sun, is very unique. Most stars are visible only at night, but our sun is visible at daytime. It is the closest star to earth. Since the star is so close to us, we are able to know much about its surface. Similar to all stars, the sun is a ball of hot gas. It has an interior as well as an atmosphere. The sun's surface is known as the photosphere. It's surface is largely uniform in brightness and becomes slightly darker on its edges. The sun is one of our sources of energy. Nuclear fusion is the process by which energy in the sun is formed. Groups of four hydrogen atoms are changed in to a single helium atom.
THE SUN AND US:
LAYERS OF THE SUN:
Close up, our sun is not as amiable. Its outer layers are extremely hot, bubbling, and full with explosions. The first layer, the photosphere, looks like the sun's surface. In the photosphere, hot gases rise and cool. These are known as convective cells. Upon reaching the surface, they look like small freckles, known as granules. The temperature of the photosphere is about 10,000 degrees Fahrenheit, which is much cooler than what is above and below. But it is the photosphere that sends heat and light in to space. These waves travel at 186,300 miles per second, and reach Earth within approximately eight minutes.
The next layer is the chromosphere. The best time to see this layer is during a total eclipse, which is when the moon blocks the sun's disk. The chromosphere appears as a thin, pink ring around the edge of the sun. The bottom part of the sun's atmosphere is irregular in terms of its shape. Its depth can vary from 1,000 to 10,000 miles. Giant flames, or spicules, make the chromosphere irregular. Spicules are made of hot gases that shoot from the chromosphere in to less dense area. They can extend up to 10,000 miles and travel at 17 miles per second.
The corona is also best studied during a total eclipse. It appears as a pearl white layer extending out around the sun. The corona is the top layer of the sun's atmosphere. It is made up of very hot, thin gases and stretches more than 1 million miles from the photosphere. Its one million degrees hotter than the sun's surface due to violent explosions from below, such as sunspots, prominences, or solar flares. With these high temperatures, the corona is constantly expanding and changing shape.