Activity at a Glance
Scale of the Planets

Purpose
To model the relative scale of the planets and their orbits.

Overview
This activity has three parts that can be used separately or in combination.

Part 1:  Planet Sizes — Children examine the relative sizes of the planets using fruits and vegetables to represent the different planets, draw the solar system, and review some key facts. Then they examine cutouts of the planets, identify each one, and place them in the correct sequence.

Part 2:   Planet Distances — Children consider the most appropriate scale to use for a model of planetary distances. Children then go outside and place the “planets” in their respective orbits. Once all markers are placed, children walk through the model, stopping at each marker to discuss the planet.

Part 3:   Solar System on a Map — Children apply their understanding of distance and use a map of their area to plot the scaled locations of the planets relative to their home.

## Concepts

• The solar system has nine planets in orbit around the Sun.
• The four inner terrestrial planets are small compared to the four outer gas giants. Pluto, the ninth planet, is farthest from our Sun, beyond the gas giants.
• Planets have some similarities and many differences.
• The distance between planetary orbits is large compared to their sizes.
• Models can help us comprehend large-scale spatial relationships.

Appropriate Ages

Part 1:  This activity is intended for ages 5–13.

Part 2 (Indoor or Outdoor Activity):

Hopping Across the Solar System is intended for ages 5–8.

Pacing Our Solar System is intended for ages 9–13.

Part 3:

Putting the Solar System on the Map is intended for ages 9–13.

Time

Part 1:  15–30 minutes (depending on detail and discussion)

Part 2:  45 minutes (either indoor or outdoor version)

Part 3:  45 minutes

Materials

Part 1:

• Books or videos about the solar system
• Solar system fruits and vegetables (Table 1 — Scaled Planet Sizes)
• Chart paper
• Paper and colored pencils, markers
• Paper circles representing each planet (Table 1  — Scaled Planet Sizes). Use newspaper, poster paper, or wrapping paper for Jupiter and Saturn. Attach the smaller planet cutouts to a piece of paper or a paper plate so they do not get lost.

Part 2:

• Softball, marbles, peppercorns, and sand to represent the planets
• 3 × 5 index cards or paper plates or bright-colored card stock with each planet representation attached if possible (Table 2 — Scaled Distances from Our Sun)
• Nine 3-foot dowels to attach to the planet cards
• Tape
• Copies of the handout:

• Hopping Across the Solar System for children ages 5–8
Pacing Our Solar System for children ages 9–13
• A large outdoor area

Part 3:

• Paper planet circles from Part 1
• Local maps (or copies of maps) with a scale, extending to 40 miles from your geographic location
• Distances from Table 3 — Mapping Distances from Our Sun
• Colored pencils
• Protractor, ruler, or string

Correlations to National Science Standards

Physical Science — Content Standard B

Transfer of Energy

• Light interacts with matter by transmission (including refraction), absorption, or scattering (including reflection). To see an object, light from that object — emitted by or scattered from it — must enter the eye.
• The Sun is a major source of energy for changes on Earth's surface. The Sun loses energy by emitting light. A tiny fraction of that light reaches Earth, transferring energy from the Sun to Earth. The Sun's energy arrives as light with a range of wavelengths, consisting of visible light, infrared, and ultraviolet radiation.

Earth and Space Science — Content Standard D

Earth's History

• The Earth processes we see today, including erosion, movement of lithospheric plates, and changes in atmospheric composition, are similar to those that occurred in the past. Earth history is also influenced by occasional catastrophes, such as the impact of an asteroid or comet.

Earth in the Solar System

• The Earth is the third planet from the Sun in a system that includes the Moon, the Sun, eight other planets and their moons, and smaller objects, such as asteroids and comets. The Sun, an average star, is the central and largest body in the solar system.
• Most objects in the solar system are in regular and predictable motion. Those motions explain such phenomena as the day, the year, phases of the moon, and eclipses.
• Gravity is the force that keeps planets in orbit around the Sun and governs the rest of the motion in the solar system. Gravity alone holds us to Earth's surface and explains the phenomena of the tides.
• The Sun is the major source of energy for phenomena on Earth's surface, such as plant growth, winds, ocean currents, and the water cycle.

Last updated
April 20, 2005

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