The sun is the source of all life on earth, providing light and warmth to the organisms that inhabit our planet. As a result, the sun has fascinated humans throughout history. This fascination has led scientists to study the sun and they often have to use technology to aid them in doing so. This sheet provides answers to the questions students should answer on their A Look at Sunspots and Modern Research on Sunspots student sheets.
Are sunspots visible to the naked eye?
Given the proper conditions such as fog, haze, or viewing the sun at sunset, it is possible to observe sunspots with the naked eye.
What problems did astronomers face by viewing the sun with the naked eye?
Due to its intense brightness, looking at the sun directly is a very difficult and dangerous thing to do. Light from the sun can permanently damage the eyes. Students may be aware of the damage the can be caused by the sun during a solar eclipse. In preparation for the eclipse, people are told to not look directly at the sun during an eclipse. That is because powerful ultraviolet radiation can severely burn and damage the eyes even though this form of light cannot be seen.
How do you think the telescope changed the study of astronomy and, specifically, sunspots forever?
Telescopes not only protect the eye from direct contact with the sun, they also allow scientists to observe the sun and other solar bodies that are far away. With the invention of the telescope, observers were able to confirm the existence of sunspots on the sun and use the instrument to make detailed observations about their size, shape, and movement across the sun.
Tell students that older telescopes, like our eyes, allow us to see in the visible light, or white light range.
What is visible light?
Students should know that visible light refers to the wavelengths of light that are visible to the human eye.
If white light were exposed to a prism, what colors would emerge?
Red, orange, yellow, green, blue, indigo, and violet.
What kind of electromagnetic radiation has the shortest wavelength? The longest?
Gamma rays have the shortest wavelength. Radio waves have the longest.)
What kind of electromagnetic radiation could be used to "see" molecules? A cold virus?
X rays allow us to "see" molecules. Ultraviolet waves can be used to "see" a cold virus.
Some insects, like bees, can see light of shorter wavelengths than humans can see. What kind of radiation do you think a bee sees?
Bees see ultraviolet radiation.
Which image depicts the sun through the use of visible light?
Allow students time to try to figure out which of the images shows visible light emitted by the sun. Then tell students which one of the three solar images is the visible light image. Label this image "Visible Light" with a transparency marker.)
Which image depicts the sun through the use of ultraviolet light?
Repeat above directions.
Which image depicts the sun through the use of X rays?
Repeat above directions.
Describe the features of the sun that can be seen using visible light that cannot be seen in the other two images using non-visible light.
Students should understand that the visible light picture of the sun shows what parts of the sun emit visible light. After comparing and contrasting the three images, students may state that the visible light image shows the surface of the sun and sunspots as dark and light regions on the surface.
Describe the features of the sun that can be seen using non-visible light that cannot be seen in the image using visible light.
Students should understand that the non-visible light pictures of the sun show what parts of the sun emit non-visible light. For example, the UV image shows the parts of the sun that emit UV light; similarly, the X-ray image shows the parts of the sun that emit X-ray light. After comparing and contrasting the three images, students may state that the UV solar image seems to show a halo around the sun. The X-ray image shows active and calm regions on the sun.)
Where does ultraviolet fall in the electromagnetic spectrum? Does it have shorter or longer wavelengths than visible light?
This a review question. UV comes after violet in the visible light range and thus, has a shorter wavelength than visible light.
Where do X rays fall in the electromagnetic spectrum? Do they have shorter or longer wavelengths than visible light? Than ultraviolet light?
X rays are at the end of the electromagnetic spectrum with the longest wavelengths. Thus, their wavelengths are longer than both visible and UV lights.)
If X rays show more detail than visible light, why do you think scientists still continue to take satellite pictures of the sun using visible light?
Each of the images shows different aspects of the sun. While X rays show details about the active vs. calm regions of the sun, visible light images detail the surface of the sun. These images used together give a more detailed picture of the sun that neither of these images could do alone.