Comparing our Solar System with the Universe

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

1. How would you compare the size of the solar system to the Milky Way galaxy?

2. What would you use to compare the size of the Milky Way galaxy to the universe?

Our solar system compared to the Milky Way galaxy.

Visit Galaxies Galore, Games and More to see what relationships exist between our Solar System and the Milky Way Galaxy.

• Black paper (4 inches by 4 inches)
• Straight pin

1. Time yourself for two minutes.  See how many holes you can poke into your piece of black paper in that time.
2. When the time is up, count or estimate how many holes you were able to poke into your paper. 
3. Do you think you were able to poke 200 billion holes? 
4. That is how many stars there are in the Milky Way galaxy. 
5. Each tiny hole represents our entire solar system compared to the rest of the Milky Way galaxy.

An activity comparing the Milky Way Galaxy to the Universe

Background:

There are billions of galaxies in our universe. Since galaxies are SO far apart, most of the universe is empty space.

Materials:

• Dime
• Meter stick
• Marker of your choice (example a penny)

Procedure:

1. Place the dime at the end of the meter stick farthest away from you. The dime represents the Milky Way galaxy. It would take you 100,000 light years to travel from one end of the Milky Way galaxy to the other end.
2. Half way across the meter stick, put some kind of a mark. It would take you two million light years to get to this mark, which represents the Andromeda galaxy. Label the Andromeda galaxy.This is our closest neighboring galaxy.
3. The rest of the universe, at least as far as astronomers can see, would extend 2 km beyond the meter stick in all directions. 
4. Keep in mind that Earth would be only a speck of dust on the dime you placed first on the meter stick.

Analysis:

1. Order these objects, according to size, from smallest to largest.
   Galaxy, Earth, Solar System, Universe, Sun
2. Highlight the box below to see if you are correct.

The image above shows how the Milky Way would look if you could see it from space compared to all the other galaxies in the Universe.