Parts of the Sun
Like other stars, the Sun is simple in its composition. Stars are giant balls of gas held together by their own gravity. They are tremendously hot and have very high pressures. In this interactivity, click on each of the spinning circles to learn more about the structure of the Sun. Click the player to begin.
Download a printable version of the interactivity.
Now that you have examined a model of the Sun, learn more about the Sun's different layers in the video The Anatomy of the Sun from eMediaVA℠. As you view the video, make note of how the scientists describe the composition of this important solar body.
Viewing the Sun
SOHO (ESA & NSA)
Concentric Layers of the Sun
How deeply can astronomers view the Sun’s layers? When looking at the Sun, even the most advanced visible telescopes do not penetrate very far. Human eyes only record the photons that escape from the Sun and travel out past the Sun's outer layers. These photons are at the proper wavelength of light to view. By choosing different wavelengths of light, astronomers are able to study the photosphere; however, gases in the corona are too thin to study, while gases below the photosphere are too dense to study.
So, how are the layers of the Sun accurately studied? It is actually a field of astronomy called helioseismology. Helioseismology studies the vibrations of the Sun, much like a geologist studies the vibrations during and after an earthquake. The Sun has around ten million different wavelengths to study, so a network of telescopes must be used. When the data is disaggregated, astronomers can determine temperature, density, pressure, composition, and the motion within certain depths of the Sun.
To learn more about the Sun's location, size, and temperature, view the NASA video Characteristics of the Sun from eMediaVA℠. As you view the video, make note of how the Sun compares to other stars, as well as to the Earth.
Solar Wind
Light and heat from the Sun reaches the earth in a matter of minutes. Gases from the Sun also travel to Earth at fast speeds, almost like a breeze. The proper term is called solar wind. These winds are composed of low density gases and can blow past the Earth at 300 to 800 kilometers per second. This means that the Sun is losing a small amount of mass each year, and it is believed that it will start to lose its mass more rapidly at some point. The Sun will not start rapidly expelling gases for another billion years or so.
The Parts of the Sun Review
Now that you have learned about the parts of the Sun, check your knowledge in this non-graded activity. Read the instructions associated with each question and select your answer. Then, click SUBMIT to check your response. Click the player to get started.