###### Solar System - Are You Really Going to Measure With That?

Journal Entry - Take out your science journal and answer the following question(s) (use drawings as appropriate):

Write what you know about the distances of the planets.

Have you ever noticed that posters of the entire solar system make it look like the planets are exactly the same distance from each other?  In fact, some planets are relatively close together, and some planets are very far apart.  Since things are so vast in the solar system, astronauts use a unit of measurement called an Astronomical Unit.

1 AU = 149.6 million km (the distance from the Sun to the Earth)

This activity will help you understand the distance between each of the planets. Remember that this is a model and is not meant to be totally accurate!

Materials:

• One roll of toilet paper- at least 40 sheets
• Chart showing the number of A.Us each planet is from the sun.

Procedure:

1. You can do this activity alone or with a group of friends.
2. You will need to be in a long hallway or outside. Unroll the toilet paper and mark each planet according to the chart.  One A.U. is equal to one square of toilet paper.
3. When all the planets are marked, observe your model.

Chart of Planet Distances

 PLANET Astronomical Units Mercury 0.4 Venus 0.7 Earth 1 Mars 1.5 Jupiter 5.2 Saturn 9.5 Uranus 19.2 Neptune 30 Pluto 39.5