Paper Plate Education
Activity: Milky Way Galaxy
The following text is excerpted from GLPA Proceedings, 1992, p. 85; used with permission:
Our sun is the nearest star of over 100 billion orbiting a central point.
This group is called our Milky Way Galaxy because we see it as a band of
light going across the sky, once thought of as a band of milk.
Most of the stars we see are near-by neighbors of our sun. A few bright
stars are more distant.
2 paper plates
some of the activities, we straighten out the wrinkles in the plates.
Do not do so for this activity. Place
the 2 plates together so the curved part of each faces toward each other.
Tape them around the edge. Now
you have something looking like a discus. Find
a point about 2/3 the way out from the center.
This is where our sun is located. The
disk of the galaxy is abut 120,000 LY (light years) across and our sun is about
30,000 LY from the center. The
outer arms are about 1,000 LY thick. The
inner bulge is like a ball at the center of your model. The bulge is 12,000 LY
across and 10,000 LY thick. Label
the LY measurements on your paper plate model.
Find other material to make a model to scale showing the central bulge.
Globular Clusters are spheres of stars in several groups above and below
the plane of the galaxy. It takes
about 250,000,000 years for our sun to go around the galaxy center.
Draw a time line around your plate and mark events that happened in the
last 250 million years.
history 5 to 10,000 years ago
Earliest humans 2 to 3 million years ago
Dinosaurs died out 65 million years ago
(end of Cretaceous - 1/4 orbit)
All continents togetherPangaea300 million years agoslightly over
Life changes from reptiles to dinosaurs during just one orbit of the sun
Oldest rocks at the Grand Canyon7 orbits ago of the sun around the
First bacteria formed about 10 orbits ago
Most of the objects in the galaxy are blocked by gas and dust so we are
unable to see them in visible light. Astronomers
now use infrared telescopes and radio telescopes to get information of what is
behind the dust. Many other
galaxies have black holes at their center.
Current research is trying to see what is at the center of our galaxy. Sagittarius is a constellation we see in the summer looking
south. A part of it looks like a
teapot. Just west of the spout from
the teapot is the direction of the center of our galaxy.
Contributed by Wayne James.
Copyright ©2012 Chuck Bueter. All rights reserved.