Lesson Plan
Lesson Title
Solar System on a Map/Solar System
Scavenger Hunt
Grade Level
State Indicator(s)
Goals and Objectives Students will get a better handle on exactly how big the solar system really
for Student Learning is by scaling down the size of the solar system to the same scale as a map of
a familiar place (your school, Columbus, Ohio, etc.).
In the process, students will practice crucial math and science skills such as
performing unit conversions (i.e., algebra) and map reading.
Diversity
Teaching Method
Learning Activities
Guided Inquiry
Science Introduction:
Space is REALLY big, and it is often hard for students (or even teachers)
to grasp just HOW big space, and even the solar system, actually is. In this
lesson, students will get a handle on how big the solar system is by making
a scaled model, based on a reference frame they are familiar with, such as
their school building, the city of Columbus, or the state of Ohio.
The distances of the planets/dwarf planet (so we can include Pluto, hence
forth simply called a planet for simplicity1) from the sun are the following
(here, distances have been put in units of both kilometers and astronomical
units, AU, where 1 AU is defined as the average distance between the earth
and the sun):
Sun to Mercury: 0.387 AU = 57,900,000 km
Sun to Venus:
0.723 AU = 108,200,000 km
Sun to Earth:
1.000 AU = 149,600,000 km
Sun to Mars:
1.524 AU = 227,900,000 km
Sun to Jupiter:
5.203 AU = 778,300,000 km
Sun to Saturn:
9.555 AU = 1,429,000,000 km
Sun to Uranus: 19.22 AU = 2,875,000,000 km
Sun to Neptune: 30.11 AU = 4,504,000,000 km
Sun to Pluto:
39.54 AU = 5,916,000,000 km
Note that these are the ‘average’ distances. The planets orbit the sun in
elliptical orbits and so are not actually the same distance from the sun at all
times. However, most of the orbits are close enough to circular that just
using a circle is a good approximation, particularly for a lesson such as this.
By choosing a scale factor, say 1 meter on school grounds = 10,000,000 km
in the Solar System, then you can apply this scale factor to all the Sun-
planet distances to get the distance each planet would be from a model of
the sun placed, say, in your classroom:
Sun to Mercury: 5.79 meters = 19.0 feet
Sun to Venus: 10.82 m = 35.5 ft
Sun to Earth:
14.96 m = 49.1 ft
Sun to Mars:
22.79 m = 74.8 ft
Sun to Jupiter: 77.83 m = 255 ft
Sun to Saturn: 142.9 m = 469 ft
Sun to Uranus: 287.5 m = 943 ft
Sun to Neptune: 450.4 m = 1478 ft
Sun to Pluto:
591.6 m = 1941 ft
This conversion can be made for any size scale factor you choose. Students
will then have to reproduce these distances based on the map that you give
with the additional scale given in the legend of the map (e.g., 1 inch on the
map = 10 ft on school grounds. The goal is to try to find the place on the
map where each planet is located, compared to some reference point where
the Sun is located.
Teacher Preparation Procedure:
1.) Determine what map/size scale you wish to use for this activity.
2.) Develop an appropriate solar system-to-map scale factor that makes
it possible to fit the entire solar system on the map (Hint: Start by
basing your scale factor on the orbit of Pluto so that you know that
Pluto’s orbit will fit on the map, and work your way inward from
there).
3.) Determine the distance to all the planets from the central region on
the map you’ve chosen for the sun by first applying your scale factor
from the solar system to the actual size scale of your
school/Columbus/whatever you’ve chosen and then applying the
scale of the map from the map legend to get your planetary distances
in map units. Example:
a.)
(True distance from Sun to Pluto, km) * (solar system to
school campus scale factor) = (distance to Pluto in physical units on
the school campus)
In other words:
5,916,000,000 km * 1 meter / 10,000,000 km = 591.6 meters,
physical distance between Pluto and the sun on campus.
b.) Distance to Pluto on campus * legend scale on map = map
distance of Pluto from sun, so
591.6 meters * 1 cm/1.5 meters = 394.4 cm on the map
between the sun and Pluto.
4.) Once you’ve determined an appropriate scale factor as well as the
scale factor of the map you’re using, determine the location of each
of the planetary orbits on the map by measuring the radius of the
orbit from the distance between the sun and each planet in map
units, and then drawing a circle of this radius around the model sun
in the center of the map.
5.) “Place” each planet somewhere within the school based on a room
that the planet’s orbit enters from your scaled map drawing.
Student Procedure:
This is much the same as the teachers, except the teacher will provide the
students with a blank map, with only the location of the sun drawn (make
sure the map contains a legend with the map scale units), in addition to the
scale unit they should use for mapping their solar system onto the map (i.e.,
the 1 meter = 10,000,000 km scale factor). The students will then need to
use this information to map out their solar system and guess the locations
within the school that you’ve ‘placed’ the planets (for real scavenger hunt
alternative, see Supplements below).
1
In 2006, the International Astronomical Union (IAU) set the definition of a
“planet” to be a celestial body in the Solar System that satisfies all three of
the following criteria: (1) it must be in orbit around the Sun, (2) it must have
sufficient mass to assume hydrostatic equilibrium (a nearly round shape),
and (3) it must have “cleared the neighborhood” around its orbit (i.e., there
are no other bodies of comparable size other than its satellites in its orbital
zone). Under this definition, Pluto is now classified as a “dwarf planet”
because it only satisfies the 1st and 2nd criteria (it shares its orbital
neighborhood with Kuiper belt objects, such as the “Plutinos”).
Materials
Supplements
Map (with scale)
Calculator
Ruler
Compass (for drawing circles, optional; alternative: two pencils and a
string)
Set of clues (for Scavenger Hunt variation, below)
Solar System Scavenger Hunt:
Turn this lesson into a real scavenger hunt with clues and prizes: If it is
possible for students to actually move about the school grounds (inside
and/or outside), a fun supplement to this lesson is to actually make either
signs or models (e.g., think Styrofoam balls) of the planets, and ‘hide’ them
along their orbits in your scaled model of your school grounds. Then make
clues for each planet, so that once your students have their scaled model
drawn on their map, they can get a copy of the clues. Based on the clues
and the areas of the map through which their orbits pass, they must go find
the true location of the planets, where you’ve hidden them.
If you cannot allow your students to actually roam the halls and grounds of
your school, a more stationary variation is to use a geographical map, of
say, Columbus, Ohio, or even the U.S. and make your clues word puzzles,
or other types of clues to get to them guess the intersection or park, etc.,
where you have “hidden” the planet. This makes the lesson more
interdisciplinary as well, including geographical facts they may need to
know in order to determine where you have “hidden” the planets.
References
Hidden Scale factor:
If you are using the stationary, map, approach, reverse the order of the
information you give them, and instead, start by giving them the scavenger
hunt word clues. By determining the location of each planet away from the
sun, make them calculate the scale factor you assumed to place the planets
in these locations.
Lesson by Kelly Denney, The Ohio State University