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.

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:

1. Open Google Maps and enter your school’s street address.
2. Zoom in on your school and look at surrounding streets and landmarks.
3. North is always up on Google Maps. Find a landmark that’s to the north of your school.
4. Put North on the wall that’s closest to that landmark.
5. 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.

Review Photos and Answers Before Class

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.

No prep required.

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.

You need an outdoor area that’s at least 60 feet long where you can mark on the ground with chalk.

Watch the Prep Video

We include an instructional video for this activity that is meant for the teacher, not for students. The video walks you through how to mark the string at particular increments with permanent marker, which needs to be prepared in advance of the activity.

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.

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.

Teacher Tips

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.