In this unit, students explore the Earth, Sun, Moon, and stars using observations of shadows and changing patterns in the sky. Students also explore the planets of our Solar System and begin to consider what might lie beyond.
THIS LESSON WAS REVISED ON JULY 1, 2019. Here is a link to the previous version.
In this lesson, students come to understand that the setting Sun isn’t moving, the Earth is spinning. In the activity, Spinning Earth, students use their bodies as a kinesthetic model of the Earth to understand how the speed of the Earth’s spin affects the length of a day.
We suggest students work in pairs. Homeschool students will need a partner for the activity.
All students will be standing up and spinning in place throughout the activity with a place to view their paper Sun model. We find that placing the Sun model on a desk and standing about a foot behind the desk works well.
If you have a lamp or bright light, you can also use this as a model for the Sun. Just remind students NOT to look directly at the bulb.
In this lesson, students will learn why our ancestors divided the day into hours and how clocks measure the Sun’s apparent movement. In the activity, Make a Shadow Clock, students make their own sundials. First, students use flashlights indoors to understand how the position of the light affects the time shown on the clock. Then, students take their shadow clocks outside to see how the position of the Sun can tell them the time of day.
We suggest students work in pairs. Homeschool students can work on their own.
Prep Shadow Clock Templates
Each Shadow Clock printout has two templates on it. Once you print these out, cut each in half so that each student will have one.
Label Classroom Walls with Cardinal Directions — North, South, East, West
When students are experimenting in the classroom, they need to orient their Shadow Clocks so the arrow points North.
Make four signs — North, South, East, and West.
Here’s one easy way to figure out where each sign goes:
Open Google Maps and enter your school’s street address.
Zoom in on your school and look at surrounding streets and landmarks.
North is always up on Google Maps. Find a landmark that’s to the north of your school.
Put North on the wall that’s closest to that landmark.
Face North. Put West on the wall to your left, East on the wall to your right, and South on the wall behind you.
Find North Outside and Draw Arrows with Chalk
The main activity is completed indoors, but we recommend that students test their Shadow Clocks outside on a sunny day. They’ll need to orient their Shadow Clock with the arrow pointing North. We recommend that you sketch several compass roses on the ground in chalk to serve as workstations.
The easiest way to find exact North when you are outside is to use a Shadow Clock. Turn the shadow clock to match the current time. Now the compass rose you made on the Shadow Clock will be properly oriented.
A magnetic compass, whether an old-fashioned kind or those available on many smartphones (such as iPhone’s compass app), actually points toward the Earth’s magnetic North Pole, which is slightly off from the geographic North Pole, depending on where you are. It may cause some error, depending on your location.
In this lesson, students discover how the Sun’s path changes with the seasons. In the visual activity, Guess the Season, students figure out the season of the year by studying a photo. Students come to realize that they can use the time of day and length of shadows to figure out the season in each photo.
Each photo has an obvious clue related to the season — like ripe pumpkins for autumn or snow for winter. Students will recognize those clues immediately.
But each photo also includes the time it was taken. Using the time and the Sun’s position, students can figure out the season using astronomical clues — like the length of the day (long in summer, short in winter) or the time of sunrise (early in summer, late in winter).
In the class discussion that follows each photo, you may need to prompt students to notice the time on the photo and think about what the time says about the season. Reviewing the questions and answers before class will help you prepare to facilitate class discussion.
In this lesson, students will be introduced to the Earth’s orbital movement around the Sun, as a means of seeing why the constellations change. In the activity, Universe-in-a-Box, students make a paper model that helps them visualize the Earth’s yearly orbit around the Sun. They use this model to understand why some constellations are only visible during part of the year.
This lesson explores why the Moon seems to change shape (phases) over the course of a month. In the activity, Model the Moon's Phases, students use a styrofoam ball as a model of the Moon and a flashlight as a model of the Sun to gain a better understanding of how the interactions between the Sun and Moon are responsible for the Moon’s phases.
We suggest students work in pairs. Homeschool students will need a partner for this activity.
Prepare to Darken the Room
It is important to get your room as dark as possible! It's worth taking the time to black out your windows and even tape curtains to eliminate cracks of light. Also, the brighter your flashlights, the better the demonstration. The flashlights we link to are particularly bright and inexpensive.
THIS LESSON WAS REVISED ON DEC 14, 2022. Here is a link to the previous version.
In this lesson, students gather evidence to support an argument that the apparent brightness of the Sun is dependent upon an observer’s distance from the Sun. In the activity, Solar Energy Explorer, students construct a model solar system and gather observations of the Sun’s apparent brightness from each planet within their model. Students then use those observations as evidence to support a claim about which planet is best suited to explore with a solar-powered planetary rover.
We suggest students work in pairs. Homeschool students can work on their own, but will need a stack of books or something similar to elevate their flashlight a few inches off the ground for their brightness tests.
Cut enough label stickers so that each pair of students will have 11 half stickers. You can also use 11 pieces of tape.
Prepare to Darken the Room
The brightness of your classroom can significantly affect student answers on their brightness test worksheet. It’s important to get your room as dark as possible while still having enough light for students to read their worksheets and move around safely. We suggest testing the brightness of your classroom before students arrive!
Make Sure You Have Enough Space
Each model Solar System extends about 3 meters (10 feet) so each pair of students will need this amount of space. If you don’t have enough floor space, a few student desks pushed together should work just fine! Students will also need enough space to walk along the side of their model Solar System for their brightness tests.
If you don’t have enough space, you can adapt the model to omit Neptune. Simply leave the strips of paper H, I, J, and K unattached. This will create a model that is 2 meters (6 feet) long. Be sure to discuss with students that Neptune is missing from their model. Have students predict how bright the Sun would appear from Neptune using their other observations.
During the brightness test, students may notice that the circle of light shining from “the Sun” (flashlight) onto their Test Rover worksheet gets bigger the farther away they move away from it.This happens because light spreads out as it travels from its source. A larger circle of light on their worksheet does not mean that the Sun is brighter. It means that the Sun’s light is spreading out, which makes it dimmer.
In this lesson, students discover that gravity exists on all planets and moons, but the amount of gravity is different because it depends on how massive the object is. In the activity, Gravity Jump, students measure how high they can jump on Earth and then calculate how high they would be able to jump on other planets and moons within our Solar System.
We suggest students work in pairs. If possible, we recommend pairing students of similar heights together. This way, when the students remove the sticky notes from the wall, they should be able to easily reach them. Homeschool students can work on their own.
Decide Where Students Will Jump
Each pair of students needs a blank space (a wall or cabinet) where they can place their sticky notes and measure their jump height. If you have enough space in the classroom this is ideal, but you can also do this in the hallway.
Set up Planet and Moon Exploration Stations Before Class
We suggest printing out two sets of the Planet and Moon Exploration Stations so that a maximum of 4 students are at each station at a time (given a class of 32 students). Each student will only need to visit 4 stations. We suggest placing one set of these stations at opposite ends of the classroom or one station on desk clusters of 4 so that students have the most room to spread out.
Teacher Science Background
We have rounded numbers to simplify the gravitational differences between Earth and other planets and moons. If you or your students are curious, the exact amounts of gravitational pull and how they compare to Earth are listed here:
Earth | 9.81 m/s2
Moon | 1.62 m/s2 | 5.98 times less gravity than Earth
Jupiter | 24.79 m/s2 | 2.55 times more gravity than Earth
Mars | 3.71 m/s2 | 2.61 times less gravity than Earth
Titan | 1.35 m/s2 | 7.18 times less gravity than Earth
Triton | 0.78 m/s2 | 12.43 times less gravity than Earth
Neptune | 11.15 m/s2 | 1.15 times more gravity than Earth
Even though they are much larger than Earth, both Jupiter and Neptune are gas planets, which means that they have much lower densities. Uranus is much larger than Earth, but because the density is much less in comparison to Earth’s, the gravitational pull of Uranus is actually less than that of Earth.
In this lesson, students discover that the Earth is in the “Goldilocks Zone” — a distance from the Sun with the right amount of light and heat for life to exist. In the activity, Star Explorer, students plan a space mission to another planet outside our Solar System based on the amount of heat and light that reaches the planet’s surface. Once students plan their space mission, they will reflect on what our Sun would look like from this far-away planet.
We suggest students work in pairs. Homeschool students can work on their own, but this activity works best if each student can engage in debate and discussion with at least one other person.
Check Shading on the Worksheets
The Mission Plan worksheets include greyscale shading that indicates the amount of heat and light that emit from each star of the three solar systems. The correct shading is essential for the activity, so we suggest printing out copies of these worksheets beforehand to ensure that everything prints correctly.
The solar systems and stars (Malina, Thea, and Helios) used in the activity are fictional, but they were inspired by real scientific discoveries. If you and your students would like to learn more about real stars and exoplanets that astronomers are investigating, there are several resources in our Extensions section for you to explore.
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