Scale Models of the Solar System (size and distance)

The sun (by Abe,) Mercury, Venus, Earth and Mars

One of the first activities we did was pace out the distances, to scale, between the various planets in the Solar System. I always think activities like this are so memorable (we did something similar when learning about the amount of empty space in an atom) and fun. It's just incredible to imagine the vast distances we are talking about even in just our own solar system! Mind-boggling.

There are a few different ways to do this---this one uses beads and strings, so you could do it inside. This one is similar ("solar system in your pocket")

This one is really great, because it shows distance AND planet size to scale, so we would have done this if I'd been more prepared. Also I really love the writing style of the guy who wrote this up (clearly a passionate astronomer)

But we ended up doing this very simple walk, using the following numbers of steps:

To Get From: 

Sun to Mercury walk 3 steps 

Mercury to Venus 2.5 steps 

Venus to Earth 2 steps

Earth to Mars 4 steps 

Mars to Jupiter 27.5 steps

Jupiter to Saturn 32.5 steps

Saturn to Uranus 72 steps

Uranus to Neptune 81.5 steps

Neptune to Kuiper Belt/Pluto 71 steps

It was really easy and it fit (barely) in the space we were trying to use. I just made really simple signs on skewers to poke in representing each planet, so we could look back and see how far we'd come.

Pluto. The inner planets are waaaay back by the purple arrow---almost out of sight

Enlarged

Next we wanted to show the relative sizes of the planets. For this model, of course, we didn't show relative distances, and we couldn't include the sun either.

We used the following dimensions:

Mercury: 1½"

Venus: 3¾"

Earth: 3 7/8"

Mars: 2"

Jupiter: 44¼" (Tape butcher paper together to get desired width)

Saturn: 37 1/8"

Uranus: 16"

Neptune: 15¼"

Pluto: ¾"

We used a compass---or a string tied to a pencil (cut to the radius of the planet we were drawing) for the  larger planets---to make the planets the right size. Just learning how to do this was educational in itself, I thought. The older boys were quite pleased with themselves.

Sam even showed them how to do an ellipse, using a loop instead of a line of string. That was for Saturn's rings.

We colored the planets after we drew them, which took forever, but looked nice. Our butcher paper kept curling because it was nearly at the end of the roll. Annoying (the planets kept curling off the wall even after we put them up). We should have flattened them under something first.

We put them up in our stairway and it was really fun to walk by them every day (when they weren't falling down). I love the dramatic size of Jupiter and Saturn next to the tiny little rocky planets!

And there's always this cool "powers of 10"-type universe scale site (did you watch "Powers of 10" in high school science class? I love that movie)