To observe stars in the night sky and develop the understanding that there are more stars in the sky than anyone can easily count, and that their placement in the sky and brightness is not uniform.
This lesson is geared toward second graders who have some experience in the area of observing the night sky. In light of this, you are encouraged to lead your students through Sky 1: Objects in the Sky so that your students can have experience with making first-hand observations of the night sky.
In these early grades, learning about objects in the sky should be entirely observational and qualitative. Students will first discuss what they already know about stars so that you may take inventory of student understanding. Then, the Development of this lesson is based on observations of slides in the classroom. While students will not discuss the number of stars they see, you will discuss with them, and invite them to ponder, the vast (uncountable) number of stars. With your guidance, these classroom exercises will help them make better observations of stars on their own.
After doing this lesson, students should be encouraged to go home and do some night sky observing on their own.
You may want to read these articles ahead of time:
- How many stars are there in the sky? is an article that posits the number of stars in our galaxy and then provides a link that discusses the number of galaxies. There is also a link to an image on the Sloan Digital Sky Survey, a project that is mapping the night sky.
- A Sky Full of Glittering Jewels discusses what properties of a star give it different colors.
You may want to bookmark these images that will be used:
Open this lesson with this question: "Have you ever looked at the stars in the sky? What was your favorite thing about them?"
Students could go in any direction with their answers. Some may give answers based on their more immediate impressions of stars, such as they have five points, or they are white or yellow, or, from the song, they twinkle. Write their answers on the board (all answers are worthy). Also, depending on your students, you could open with a different question, such as, "What do you know about stars?" As long as it gives you an opportunity to find out if they have done any independent observing and what they may already know.
In this portion of the lesson, students will observe stars from online pictures. We highly recommend that you project the pictures from a computer (or laptop) onto a large screen at the front of the classroom. You will likely need to close the shades and turn off lights for the best viewing. (If you don’t have this particular setup, students can gather around one or two computer screens as you pull up the pictures.)
Independent Project: If students are computer savvy and your school has ample computers, have each student go to a computer and follow along with you on the Star Observation student esheet. The esheet also has the questions written out. For some second graders, the student esheet could offer an extra credit lesson done independently.
Bring up the Astronomical Stars image on the Gateway to Astronaut Photography website. Ask this question:
- What do you notice about the stars in this picture?
(This is an open question that invites students to really observe. You will ask this same question for each image and then lead them into the answer you’re looking for only if needed. All observations are good, but what you’re after for this one is that the stars are of different brightness and that they are not scattered evenly. Of course, if they don’t observe this on their own ask, "Are the stars all the same brightness?" and "Are they evenly scattered?")
Open the next picture, named Quintuplet Cluster on the Great Images in NASA website. Again, ask:
- What do you notice about the stars in this picture?
(The stars are different colors in this picture. Students will not likely need any leading for this observation. When they do their independent observations, they won’t see such brightly colored stars. If they ask why, you can point out that scientists use special equipment to take pictures of stars way out in space.)
Open the next image, Milky Way on the Catching the Light website and ask students again to make observations. They may comment on the vast number of stars in this picture of our galaxy, the Milky Way. If they don’t, ask:
- Do you think there are a lot of stars in the sky?
(Numbers of this proportion are difficult even for adults to process. As the text says, in our galaxy alone there are more than 200 billion stars, but you want your students to know that there are a LOT of stars in the sky—more than hundreds. You may want to make the comparison of the number of grains of sand on a beach if you think they would understand.)
With the final picture, be careful not to drag the arrow over the image because it brings up the outline of the Big Dipper. You will do this in a minute, after students are done observing. Open the final image, Big Dipper on the Catching the Light website.
- What do you notice about these stars?
(It’s fine if students have the same observations over and over. Some may recognize the Big Dipper.)
- Have you ever seen the Big Dipper in the night sky? Does anyone see the Big Dipper in this picture?
(After students find the Big Dipper, drag your arrow across the image and the outline will show up.)
Keep the image projected on the screen, turn on the lights and hand out the student sheets and stickers. Instruct students to use their star stickers to make their own Big Dippers on their student sheets. If they would like to draw or color in the other stars and time allows, that is fine.
You may want, at this point, to share with students that observation and recording information are an important part of science.
To emphasize what students have learned in this lesson, go back over the list of things they brainstormed in the Motivation, the things they knew or liked about stars. You should review what they have just observed in this lesson and ask them to write or draw their new observations on their student sheets. Tell students:
- Let’s review what you observed. In the space provided on your student sheet, you should list all the observations you made about stars.
(In their observations, students should now know that: some stars are brighter than others; they are not evenly scattered; stars can be different colors; there are a lot of stars in the sky, probably too many to count. Students may not make these exact observations, but they should know more than they did at the beginning of the lesson.)
An excellent follow up to this lesson would be to assign students to go home and observe the stars on their own. You could follow up with a brief discussion of what they observed and how their observations may have differed from the images in class.
Make Your Own Star Clock, at the Lawrence Hall of Science website, helps students realize that the stars are in different locations in the sky depending on the time.