Materials: Poster boards, printed write-ups of the planets, rubber cement, 2in. styrofoam ball, 3 sm. needles, 2 sm. pins, 2 med. pins, 2 lg. pins.

Building Instructions: Rubber cement printed write-ups of the planets to poster boards. Stick pins in appropriate boards. Place boards at scale distances.

Function and Use: This display shows the solar system in a very special way. Normally, in school, you draw the planets to scale then you draw their orbital paths to scale. This display puts everything in the same scale (1 inch in the model is 400,000 miles in the real solar system!) so that what you see is a very accurate model of the solar system. You should immediately be struck by the vast empty spaces involved and you may even think of the vast empty spaces in the atoms (between the nucleus and the electrons).

As you place the display boards on the ground, take the time to read them and look at the size of the object that represents that object in this model. Most of the objects will be very tiny – being the size of the object at the tip of the pin stuck in the board. When you get to Earth, take the time to look at as many objects as you can see. This is the size they would actually appear to your eyes here on Earth. As you can see, most of the planets appear as tiny specks and the sun is only a small (aspirin at arm’s length) object as well. I hope you will take the time to walk the entire length of the hallway and observe for yourself the ‘true’ distances and sizes of the planets and read the fact sheets attached to the boards.

Scales to Use: Below are the scaled distances (in paces - # steps to the object – this is roughly About and sizes for a 250 yd. (meter) long solar system (about as long as most people can find at school). This is about 1"=25,000 miles (1 yd = 900,000 miles).

Scaled Distance (steps/paces) Object’s Scaled Size

Sun 0 2" ball

Mercury 2.5 small needle (.0075")

Venus 2.25 small pin head (.02")

Earth 1.75 small pin head (.02")

Mars 3.5 small needle

Asteroid Belt between Mars and Jupiter too small to represent

(I usually show this and give a rough idea how small these objects really are – it’s not like in the movies, going through a bunch of large rocks in space!)

Jupiter 23.75 large pin (.275")

Saturn 23 large pin (.175")

Uranus 62.25 medium pin

Neptune 70.25 medium pin

Pluto 60.5 tiny needle

Closest Star (Proxima Centauri ~4.2 light years ~ 25.2 trillion miles) 971 miles at this scale!!!!