This lesson is designed for middle school students with no previous knowledge of astronomy or the history of astronomy. This activity requires quite a bit of prep work, especially if you want students to calculate the scaled diameters and distances. This activity can take from 45 minutes to a full hour or more depending on how long you spend on the walk and how long you spend "debriefing" with your students.

Group Size:


Learning Objectives:

  • Understand and visualize the magnitude of the universe

Guiding Question:

Why was the Scientific Revolution important and how did it contribute to progress?


Accurate diameters and distances for each planet in the solar system. Model magic/play-dough/clay/other to create model planets. A large yard, field, lot, sidewalk, etc. A print-out of this lesson or your own notes so that you have numbers and facts at your disposal during the walk.

Additional resources:



[Note: This activity in its entirety can be found as an attached pdf and doc file]

Activity Prep:

  • Determine the scaled dimensions of the planets and distances with students (Optional)
  • Create planet models
  • Set up solar system
  • Complete walk through the solar system with students

Activity: A walk of the solar system

Sometimes it can be extremely challenging for students to understand the magnitude of the solar system, even with scaled diagrams. So, I find this activity to be extremely useful in helping students wrap their heads around the magnitude of the solar system.

This activity requires the use of a large field, I use the public park next to our school, or any other long stretch of land/sidewalk/pavement/etc. as well as some model magic/play-dough/other modeling clay. You and your students will literally walk across the solar system examining to-scale spheres that represent each of the planets. I also like to throw in some tiny spheres to represent the Asteroid Belt and the Kuiper Belt.

I create small model-magic balls—preferably out of colors that represent the planets (e.g., grey for Mercury, blue and green for Earth, red for Mars, white (for the cloud cover) for Venus, orange and white striped for Jupiter, yellow for Saturn, aqua for Uranus, and blue for Neptune)—and use these “planets” for the Solar System Walk. As an extension, I have students determine the diameters of the scaled planets in a math lesson. This also helps us determine the scale for the walk.

This activity was modeled after the “Scales of the Universe” exhibit at the Rose Center for Earth and Space, American Museum of Natural History.

The scale and conversion charts are attached here:

Scaled Conversions (pdf)

Scaled Conversions (doc)

Create the Sun and planets:

Sun – 8 inches in diameter
Mercury – 0.03 inches in diameter
Venus – 0.08 inches in diameter
Earth – 0.08 inches in diameter
Mars – 0.04 inches in diameter
Jupiter – 0.89 inches in diameter
Saturn – 0.75 inches in diameter
Uranus – 0.33 inches in diameter
Neptune – 0.30 inches in diameter

I like to place my solar system objects out prior to the lesson. Remember, you’ll need a large field, lot, strip of pavement, etc. to set this up accurately.

I approximate one LARGE step (roughly 3 feet for each yard) so that I don’t have to take my tape measure with me, but feel free to be more precise than I am!


Sun to Mercury - 10 yards
Mercury to Venus - 9 yards
Venus to Earth - 7 yards
Earth to Mars - 14 yards
Mars to Jupiter - 95 yards
Jupiter to Saturn - 112 yards
Saturn to Uranus - 249 yards
Uranus to Neptune - 281 yards

For the actual lesson I take my students out and read them the following introduction:

You have seen diagrams of the Sun and the planets in our lessons. The fact that the planets are very small compared to the enormous distances between them is hard to comprehend. In order to try and wrap our heads around the scale of the solar system, we’re going to take a ramble through a scale model of the solar system.

If you’ve opted to have students do the conversion calculations for the scale, then they should know the rough distances, however I find that students still have difficulty visualizing what the solar system looks like.

So, off we start, I try to make our ramble a bit dramatic, and ask students what hypotheses they can make about the planets based on what we’ve learned so far (e.g., how hot do you imagine Mercury to be since it is so “close” to the Sun? How fast do you think it’s orbit would be compared to Jupiter’s? Would you expect to see Jupiter retrograde like Mars since we also overtake Jupiter in orbit? Etc...) I find that asking students questions preps them for the planetary lessons that are soon to follow, and also makes that information more intuitive.

Finally, once we’ve walked the entire length to Neptune (by the way, the students are shocked at how far we have to walk and how tiny the planets are) I have one student stand next to each planet and we take a picture of the solar system with our student markers.

When we get back to the classroom, I like to set out our planet models and print out the picture of the students in the solar system to hang above them so that the students have a visual reminder of the vastness of the solar system over the coming lessons.


At the end of this lesson, ask students to reflect on this experience. We have a group debrief where I ask students questions like, "What was most surprising to you?" "What did you learn from this experience?" "How did this activity make you think differently about the solar system?"

Attached Files:

Magnitude of the Solar System Activity (pdf)

Magnitude of the Solar System Activity (doc)

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