When the sun is shining in the sky, it looks like a big ball of light. It’s actually a lot more complicated than that. The sun has layers and it also has places where it looks bumpy or spotty.
The center of the Sun is thecore. It’s very dense but very hot, so it is a gas. Its temperature is 15 million kelvins (27 million degrees Fahrenheit)! In the core of the sun, nuclear reactions calledfusionmake energy in the form ofgamma raysandneutrinos. This area has a radius of about 90,000 miles.
Theradiative zoneis about 190,000 miles thick. This area delivers the energy from the core into other parts of the sun.
Next to the radiative zone is the convective zone. Here, the photons of energy move faster than in the radiative zone. This is because they move on rising and falling currents of gas in a process called convection. On earth, currents like this help make the wind. The convective zone is 125,000 miles thick.
Outside the convective zone are three layers. Thephotosphereis the layer that we actually see when we look into the sky, and surprisingly, it’s only about 300 miles thick. It contains energy that’s in the visible light spectrum. Thechromosphereis outside the photosphere and is just over 6000 miles thick. It’s very hot, but it’s only visible with special instruments that help us see infrared light. The outer layer is called thecorona, and it’s the hottest part. It’s also the widest at around 3 million miles thick.
The heat moves giant solar winds around the open spaces on the Sun. In addition to layers, the Sun also has irregular areas calledsunspotsandgranules. Sunspots are dark, oddly-shaped areas on the surface of the Sun, and they appear and disappear. In 1609, the invention of the telescope helped early scientists such as Galileo and Christoph Scheiner observe these spots. At first they weren’t sure what the spots were and thought that they might be moons crossing the Sun. Galileo then determined that the spots were actually on the surface of the Sun. Today we know that sunspots are caused by magnetic activity that changes the patterns of motion in the Sun. The dark middle part of a sunspot is called theumbra. The umbra is cooler than the rest of the sun and has a strong magnetic field. It’s surrounded by a ring called thepenumbra. Sometimes the surface of the sun looks bumpy like sugar crystals. These bumpy areas called granules are areas of the sun where hot material comes to the surface before fading quickly.
Create a three-dimensional model of the interior of the sun.
- One stick and press LED tap light
- One yellow paper lantern
- 5 different colors of construction paper
- Yellow poster board
- Clear tape
- Black, red, and orange paint
- Use your paper lantern while it’s closed and flat to trace a circle on lightweight yellow poster board.
- Cut out the circle you drew.
- Expand your lantern. Divide it into halves and then quarters.
- Cut out the quarter of the lantern. This is the place where you’ll add the circle to show the different layers of the sun.
- Now cut out circles of different colors of construction paper to represent the layers of the sun. Choose a color of paper for the core, the radiative zone, the convective zone, the photosphere, and the chromosphere. Use your calculator to determine the ratios of the layers. For example, if you make the core 1 inch deep, your radiative zone is a little more than double the size of the core, so it would be 2 inches wide. The convective zone is about 65 percent the size of the radiative zone, so it would be just over 1.5 inches wide.
- Label the layers with their names and thickness and any interesting facts that you can fit onto the piece of paper.
- Glue the layers onto the circle of yellow poster board and wait for the glue to dry. Then fold the circle in half. Open it so that the edges of the semicircles form a 90 degree angle.
- When you’ve finished adding the layers, use clear tape to fit the layers into the gap you cut out in the fourth step.
- Use paint to add convection currents, sunspots, and granulation on the outside of your lantern.
- If your lantern came with a wire support, use that to stick your tap light into the lamp. If not, fix the tap light on the inside of the lantern at the bottom where you can still reach in and turn it on.