Build a Scale Model of the Solar System
Written by Fraser Cain
Everyone seemed to enjoy the answer to my daughter's question, "what's the biggest star?", so I thought I'd give you another insight into space science at the Cain household. A couple of months ago, we built a scaled map of the Solar System. I thought I'd share my process and resources with you, and throw in a few cute pictures of the kids. So come on, let's build a solar system in your neighborhood.
This project happened when I casually mentioned to Chloe that it might be fun to build a scale model of the solar system. You know, some day, when we had time. Chloe and Logan thought it was a great idea, and even though there was half a metre of snow on the ground, it had to happen… right now!
We decided that we wanted to put the Sun in Chloe's room, and then put all the planets to scale, so that we could walk to Chloe's school (about a kilometer away), and have all the planets fit nicely - we even included Pluto (which will always be a planet in our hearts).
I found a great calculator that lets you calculate various scale model versions of the Solar System. You put in the size for the Sun and then it calculates both the diameters of the scale model versions of the planets, as well as the scale distances.
We were really fortunate. A version of the Solar System that fit within the distance from our house to Chloe's school allowed for a Sun that could be cut out of a single sheet of printer paper. I used a protractor to measure out the circle for the Sun, and then cut it out. While the kids were colouring it yellow, I made tiny versions of all planets.
Here are the sizes:
| Object | Size (mm) | Size(in) |
| Sun | 200 | 7.8 |
| Mercury | 0.6 | 0.0275 |
| Venus | 1.7 | 0.0684 |
| Earth | 1.8 | 0.072 |
| Mars | 0.9 | 0.0382 |
| Jupiter | 20 | 0.7892 |
| Saturn | 16.7 | 0.6586 |
| Uranus | 6.7 | 0.2655 |
| Neptune | 6.5 | 0.257 |
| Pluto | 0.3 | 0.012 |
Then we put our mock planets out into their proper orbits using clear sticky tape. With the Sun just inside Chloe's room, Mercury was at the top of the stairs. Venus was just outside our front door. Earth at the end of our sidewalk. Mars is on a parking sign across the street from our front door. Jupiter is part way down the next block, stuck to a tree. Saturn is on another tree further down that same block. Neptune is on a parking sign 2 blocks further. Uranus is on a fire hydrant. And finally, tiny Pluto was affixed to a power pole just in front of Chloe's school.
If you want to get really clever, you can even put in tiny moons. For example, you could put in the moons of Pluto: Charon, Nix and Hydra.
Here are the kids with Mars. Look closer, it's there.
Here are all the distances:
| Object | Distance (m) | Distance (feet) |
| Sun | 0 | 0 |
| Mercury | 8 | 27 |
| Venus | 15 | 51 |
| Earth | 21 | 71 |
| Mars | 32 | 107 |
| Jupiter | 111 | 367 |
| Saturn | 205 | 673 |
| Uranus | 412 | 1353 |
| Neptune | 647 | 2121 |
| Pluto | 850 | 2787 |
I was fairly careful measuring distances for the inner planets. But then I just made a rough estimate of my stride length, and used that to mark off the longer distances. Here's a link to a stride length calculator.
It's scary to think that a version of Alpha Centauri at this scale would still be 5804.4 km (3606.7 miles) away. That would require a road trip across Canada.
And, now, every day that I walk Chloe to school, we follow the route of our miniature Solar System, and think about just how big the place really is. Even though it's been a few months since we made our model, most of the planets are still there (we lost Saturn a few weeks back, but we'll replace it).
Have you built a Solar System for a school project? Let me know how it went and send pictures. Maybe I'll do a follow up with some more astronomy project ideas.
For extra credit, get your kids to model some of the recently discovered extrasolar planets. Here's a page that lists their sizes and distances from their parent stars. With so many hot jupiters out there, you could fill a wall with scale versions.
If your kids want to learn more about the Solar System, listen to Astronomy Cast. We did a special tour through each of the planets in the Solar System. Start your tour here with Mercury, then Venus, Earth, Mars, the Asteroid Belt, Jupiter, Jupiter's Moons, Saturn, Saturn's Moons, Uranus, Neptune, Pluto, and then the outer reaches of the Solar System.
Filed under: Astronomy For Kids
April 9th, 2008 at 11:46 am
I think having astronomy with relation to kids is an excellent way to go. It gives a different, more warm kind of feel to the site and also has some interesting articles. I remember doing a scale model solar system back in highschool for a project in about the same size scale. It was over a slightly larger area as I based the sun at the centre and showed where each planet would be at during the next cycle of its orbit at what time frame. Made for a fun 2 weeks, although scale sizes were harder, so the planets were slightly larger than scale size
April 9th, 2008 at 12:12 pm
What, no asteroid belts? Maybe some flour sprinkled between Mars and Jupiter would do the trick!
April 9th, 2008 at 12:31 pm
Keppel Croft Farm in SW Ontario, Canada, has a great solar sysetm model. It's about 400m long, Sun to Pluto — and there's a garden in Vancouver which has Alpha Centauri to scale with this model as well, for distance and size!
April 9th, 2008 at 1:40 pm
wow !!! haha kids
April 9th, 2008 at 5:00 pm
Superb Fraser, a real learning experience for Chloe and Logan as well as everyone else! Looks like they had a great time - I might give it a go in my neighborhood
Ian
April 9th, 2008 at 11:18 pm
to far away for pluto that is about 1/2 a mile!!!!
April 10th, 2008 at 1:20 am
Thanks for sharing this with us Fraser !
we loose some insight with numbers, especially for kids. this is definitely the best way to show the different orders of magnitude.
April 10th, 2008 at 4:51 am
I remember being in elementary school in Eugene, OR and taking a field trip to Alton Baker Park to learn about the solar system from the scale model they have there. It was over 6km long and was a nice walk through the park, very cool i dea. Eugene's Scale Model Solar System
April 10th, 2008 at 5:50 am
Chloe is cute…….
Takes after her mother, eh?
April 10th, 2008 at 7:18 am
Several years ago I taught a year-long class in astronomy at the middle-school level, at what was unfortunately the School From Hell. No curriculum had been provided; I made it up as I went. One week I had my kids construct a scale model of the sizes of the planets, though unfortunately these kids were so nasty that I had to do the scale for them. One other time I managed to get them to behave well enough to take them outdoors on the athletic field, with a string I'd carefully measured for the relative distances of the planets. It actually got some of them thinking!
I am VERY impressed that your kids wanted to do this sort of thing. It gives me hope.
April 10th, 2008 at 7:57 am
I did a school project with (a lot of) help from my father when I was 12. For the solar system to fit in the classroom, and still be able to see the planets, we had to exagerate the planet sizes by a factor of 1000. My dad had a roll of paper and we took 6 metres of paper to do the thing. I learned a lot about the scale of the solar system this way. I don't have pictures of the project unfortunately, however I think the roll is still in a box somewhere in the attic!
April 10th, 2008 at 5:57 pm
Some xtra teeth might help your kid become a real movie star/planet. She sure is cute.
April 11th, 2008 at 6:22 pm
Great job, Fraser! That's the kind of involvement that will get the next generation excited about the Universe and our place in it. When I was a kid, in pre-Sputnik times, my dad an I would try to imagine what kind of "payload" could be sent to the moon in a container the size of a soda can. We didn't have any idea that the scale of real-life projects could get as big as they are. It was a fun mind exercise.
April 13th, 2008 at 7:05 am
Haha Ian, great idea and then set up some black holes from LHC, or even better, some primordial ones when you build your version of the scale model.