Discovering Scale Using Our Solar System
Objectives
Participants will:
- Explain the concept of scale using the
Earth and Moon.
- Build a model of the solar system to
scale using beads.
Suggested
Grade Level
3rd-5th
Subject Areas
Science
Math
Social Studies
Timeline
Two Class Periods
Standards
Science
NS.K-12.4 Earth and Space Science
- Properties of earth materials
- Objects in the sky
- Changes in earth and sky
Math
NM
3-5 Measurement
- Students
will understand the need for measuring in standard units.
Math
NM.ALG.PK-12
Use Mathematical Models to Represent and Understand Quantitative Relationships
Social
Studies
NCSS
People, Places and Environments
·
Encourage
learners to construct, use, and refine maps, calculate distance, scale, and
organize information.
Background
Scale is a difficult concept for
students to grasp. Creating 1:1 scales, or full sized maps and models, is a
good start when discussing this mathematical concept. A real life application
for using scale is reading maps. We need to be able to do math and discover
correct distances when going from one town to another. Cartographers (map-makers) cannot just guess
sizes and distances on maps or there would be a lot of lost people wandering
around looking for their destination saying “it’s around here somewhere.” Scale
is a very precise math; not a guess.
A
very great misconception in the science world is the scale of the planets in
our solar system. We are going to give students a greater cognitive
understanding of scale using the planets in our solar system. Oftentimes,
pictures depicting the planets and moons are created without taking scale into
account. This is what causes these misconceptions to formulate in students’
minds. Scale is a mathematical concept that you can create a model of a larger
object in correct proportions. For example, NASA can create a 1:15 scale model
of a rocket, be able to take measurements of that model, and from there make
decisions about the full sized rocket without going to the trouble of measuring
the 50 foot tall rocket itself. It is almost impossible to wrap our minds
around how big the solar system is and how spread apart it is. So creating a
small model of the solar system gives students a much better idea of the
correct proportions and just how big space really is.
Vocabulary
Hypothesis, Scale, Model, Solar System, Planets,
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
Materials
Butcher Paper (two pieces per student)
Photos of space models at various scales (examples
below)
Globe
Variety of different sized balls
Tennis Ball
8 planet beads per group (one orange, one
red, one light blue, one dark red, one brown, one tan, one green, one blue)
1 piece of string per group
94 black spacer beads per group
String
Copy paper
Crayons/ Markers
Books about space
Lesson Day 1
- Give each
student a piece of butcher paper, roughly the size of the top of his or
her desk. Ask students to place a few objects on the butcher paper and trace
them with a marker. (Objects could include books, notebooks, pencils, glue
bottles, etc.)
- Explain that
students have just created a map of their desks. Introduce the word
“scale.” Tell students that the scale of their map is 1:1 or “full scale”.
In other words the map is life sized: the actual size of all the
objects. Pose the following
questions to students and allow them to discuss:
a. What do we use
maps for? To help us find which way to go.
- If you
created a 1:1 map of the school would be very helpful? No. Because it
would be exactly as big as the school and you couldn’t use it to find
your way.
- Show
students photos of models of different space objects at various scales.
Ask why we build space shuttles at 1:15 scale. If we built it 1:1 it would
be way too big. Building it to scale means everything is in its proper
place. People could take measurements of the models, do some math, and the
numbers would be accurate. (See examples below)
- Tell
students they are now going to create a 1:2 scale drawing of their desk
map. Because it is 1:2, students need to divide every number in half. For
instance, if the whole map was 2 feet by one foot, in scale it is 1 foot
by six inches. If their notebook is 11 inches by 8 inches, to scale it
would be 5 ½ inches by 4 inches. When
they are finished with their map they will give it to a partner and have
them read the 1:2 map and try to re-create the full-scale map using the
correct objects.
- Explain that
you are now going to discuss scale using the Earth and Moon. Hold up a 9
in diameter globe and say that this will represent the Earth. Ask students
if this globe is the actual size of the Earth. No it is not. It is to
scale. A full-sized model of the Earth would not be helpful because it
would be as big as the planet.
- Show
students a variety of different sized balls from a bouncy ball all the way
up to a basketball. Ask students to predict which ball was the correct
size to be our globe Earth’s moon. Allow students to discuss among
themselves, and then pick a few to come up and explain their reasoning. Tell
students that the tennis ball is the correct size.
- Now ask
students how far away they think the Moon is from the Earth in our model.
Pick a few to come up and stand where they think the moon would be.
- Using string, show
students how far apart the Moon and Earth should be. The distance from the
Earth to the Moon is about the same as 9 and ½ times around the earth. So,
if you wrap a piece of string 9 and ½ times around the globe, that will be
how far away the tennis ball Moon model should be from the globe Earth.
- That seems to be
a really far distance. Ask students if they are surprised by this
information.
Lesson Day 2
- Begin by
reviewing the concept of scale from yesterday.
- Explain that
in the model yesterday both the size of the Earth and Moon were correct
and the distance between them was correct. Tell students that in our model
today, the distance between planets will be correct, but the size will not
be correct. Sometimes, as scientists, we need to pick only one thing to
focus on. Today’s focus is correct scaled distance.
- Place
students in groups and pass out the planet beads and a handful of spacer
beads to each group.
- Write on the
whiteboard what planet each color bead represents. Mercury=Orange,
Venus=Red, Earth=Light Blue, Mars=Dark Red, Jupiter=Brown, Saturn=Tan,
Uranus=Green, and Neptune=Blue.
- As the
students to make a hypothesis in their groups about how far apart all the
planets are from each other. (Have a quick discussion to activate
background knowledge about what a hypothesis is.) Have them lay the beads
out on a desk and place black spacer beads in between the planet beads. Have
students draw a picture of their hypotheses.
- When they
are done, ask them to count the total number of beads in their solar
system. Then have one person from each group line up in order from
smallest number of beads to greatest number of beads.
a. Discuss good
character and how we all have different ideas. It’s not okay to make fun of someone
for having a different idea than you. Our
classroom should be a place where our classmates feel safe (to quote Ms.
Frizzle) to take chances, make mistakes, and get messy.
7.
Pass out the pieces of string. As a class, read
aloud the following chart and have everyone put the beads on the string
correctly.
|
1 spacer
|
|
Mercury (orange bead)
|
|
1 spacer
|
|
Venus (red bead)
|
|
1 spacer
|
|
Earth (light blue bead)
|
|
1 spacer
|
|
Mars (dark red bead)
|
|
12 spacers
|
|
Jupiter (brown bead)
|
|
14 spacers
|
|
Saturn (tan bead)
|
|
30 spacers
|
|
Uranus (green bead)
|
|
34 spacers
|
|
Neptune (blue bead)
|
8.
Ask the students to discuss in their group if their
hypothesis was correct. Then they need to draw a picture of what their string
of beads looks like now.
Extensions
·
Each
black spacer bead is equivalent to 30 million miles. Have students find the
distance between Mercury and Neptune using their string of beads. They need to
work in their groups to do the math. Then, they must write a paragraph
explaining how they solved this problem.
·
Have
students look through assorted books about space for any information regarding
planetary scale. They can share what they find with the class.
Evaluation/Assessment
Informal
observation: students working collaboratively together in groups and all
students are participating
Drawing of
hypothesized bead solar system compared to accurate drawing of bead solar
system
Completed solar
system string of beads (one per group)
Resources
Space Foundation
Lesson- Play-Doh Scale Solar System
Space Foundation
Lesson- Pluto’s Not a Planet
Examples
of space models to scale: Would use larger pictures and hands on models with
students.