Monday, June 6, 2011

Backyard Solar System

We are currently learning about the Solar System, and this was a fun and easy activity I wanted to share with you.

It was quick to pull together, cost nothing, and gave us a tangible idea of the relative size of the planets and their relative distances from the sun and each other. (FYI, I am including Pluto as a planet in all of our Solar System activities. Some scientists still go back and forth on whether or not it's a planet, so I've decided that we're going to be old school and consider it one.)

What you need:
  • 9 round objects with the following diameters. (You can use balls, marbles, fruit, whatever you have on hand. If you don't have things with these exact diameters, just ball-park it. That's what we had to do for Uranus and Neptune. For Saturn we made a super-quick model out of butcher paper because I nothing else even close to that size. I had used our only large ball for Jupiter.)
Mercury: 1½"
Venus: 3¾"
Earth: 3 7/8"
Mars: 2"
Jupiter: 44¼" 
Saturn: 37 1/8"
Uranus: 16"
Neptune: 15¼"
Pluto: ¾"
  • A large space approximately 100 ft. long

What You Do:
  • Explain to your children that your planet models are not accurate in terms of colors and markings, but that the purpose of this activity is to give them a general idea of how big and small the planets are compared to each other and an idea of how far apart they are from each other. (The concept of "relative" was a hard one for my 5 and 7 year old to grasp. I also made sure they understood that the planets are not really the size of these objects but are bigger than we can even imagine.)
  • Line the planets up in their order from the sun. Place them right next to each other so that your child can really see how they compare to each other in size. (See above photo.)
  • Now pick up the planets, distribute them among you and your children and get ready to walk with them! Laundry baskets are helpful for toting all of those balls and pieces of fruit. :) 
  • Choose something (or someone) to be the sun. I wanted us to really get a grasp of how large the sun was compared to the earth, so I chose our house to be the sun.
  • Start at your designated sun and take one step away from it. Lay down Mercury.
  • From Mercury, take 1 more step. Lay down Venus.
  • From Venus, take 1/2 step. Lay down Earth.
  • From Earth, take 1 1/2 steps. Lay down Mars.
  • From Mars, take 9 steps. Lay down Jupiter.
  • From Jupiter, take 11 steps. Lay down Saturn.
  • From Saturn, take 25 steps. Lay down Uranus.
  • From Uranus, take 27 steps. Lay down Neptune.
  • From Neptune, take 24 steps. Lay down Pluto.
  • Now go back to the sun and "walk the planets", having your child name them as you go. Have them take a look at the distances and talk about how close together some planets are and how far apart others are. 
  • You can also point out the inner planets (Mercury, Venus, Earth, Mars) and outer planets (Jupiter, Saturn, Uranus, Neptune, Pluto). You can also lay down several rocks to represent the asteroid belt that lies between the orbits of Mars and Jupiter.

Stepping off the distance between the planets

Sweet Pea and Neptune

It's a long way from Jupiter to Uranus.

This Solar System activity is not to scale, although it did give us somewhat of a feel for planet sizes and distances from the sun. 

However this activity is to scale. I hope to do it at some point during our unit after we find a large enough area for it. I'll let you know when we do!

I will be sharing more Solar System fun in the coming weeks.

Have a great week!


  1. Fun learning activity! I remember doing something similar with my sons using felt "planets". We attached the planets to the siding of our house, showing their relative sizes, distances from the sun, and distances from each other. Actually,I like your activity better because its more kinesthetic.

  2. Thanks ladies for your kind comments.
    Sara, I like the idea of felt planets...I might try to make some if I can find the time.


I enjoy reading your comments and so appreciate them. It usually takes me a few days to reply, so thanks for your patience and for dropping by!