# NASA - National Aeronautics and Space Administration

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Measuring the Distance
Teacher Section

Objective: To compare the planets Earth and Mars and to demonstrate the distance between the two planets.

Grade Level: K-4
Subject(s): Science, Mathematics, Technology
Prep Time: < 10 minutes
Duration: One class period
Materials Category: Special

National Education Standards
Science
Earth and Space Science
Structure of the Earth system

Mathematics
Understand meanings of operations and how they relate to one another
Understand various meanings of addition and subtraction of whole numbers and the
relationship between the two operations
Use mathematical models to represent and understand quantitative relationships
Model situations that involve the addition and subtraction of whole numbers, using
objects, pictures and symbols
Specify locations and describe spatial relationships using coordinate geometry and other representational systems
Describe, name and interpret direction and distance in navigating space and apply
ideas about direction and distance
Apply appropriate techniques, tools, and formulas to determine measurements
Use repetition of a single unit to measure something larger than the unit, for instance,
measuring the length of a room with a single meterstick

Technology
Students will develop an understanding of and be able to select and use information and communication technologies
Materials:
• Two poster board sheets
• One roll of toilet paper
• Crayons/markers
• Student Page
• Computers with Internet access
• Pencil
Pre-lesson Instructions
• Duplicate the Student Page.
• Display the Information Sheet so that students are able to copy the information.
Background Information

Mars is the fourth planet from the Sun and the most Earth-like planet in our solar system. It is about half the size of Earth, has a dry, rocky surface and a very thin atmosphere. Traveling to Mars isn't a new idea. We've done it for several decades. The new and interesting idea is sending humans to land there instead of robotic rovers. When humans travel to Mars, they won't be going by Space Shuttle. The Shuttle is designed specifically for low Earth orbit, and Mars is a more long-distance flight.

The Moon is 384,400 kilometers (km) (240,250 miles) from the Earth. Mars is 200 times that distance from the Earth. A trip to Mars will be very complex. In order to have the supplies needed to set up facilities on the planet, multiple trips to Mars will be required. In some cases, several launched vehicles would rendezvous in space and land on Mars as a unit.

Guidelines
1. Discuss space travel today. After talking about the Space Shuttle and the International Space Station, tell students about the future plans to go to Mars.

2. Tell students that to give them an idea of how far Mars is from Earth, they will make a model that shows the distance.

3. Before they begin, have the students use the Mars/Earth fact sheet to complete information cards about Earth and Mars.

4. Discuss how far away each planet is from the Sun and have the students try to figure how far apart they are from each other. The students should subtract the distance of Earth and Mars from the Sun. Ask the students to try to imagine that distance. Make sure they understand that it is millions of kilometers.

5. Tell students that they will make the model using toilet paper. One square in the toilet paper represents 16,000,000 km (9,942,400 miles). Ask the students: If Mars is 79,000,000 km (49,090,600 miles) from Earth, how many squares should be used to represent this distance? Almost five squares. Ask students to explain how they found this answer.

6. Place the students in two groups. Give each group a poster. One group will be assigned Mars and the other group Earth. The groups will illustrate their assigned planets, making sure they show the characteristics of their planets.

7. Hang the posters up in the classroom or hallway, and connect them with the toilet paper to demonstrate the distance between the two planets.
Discussion/Wrap-up
• Discuss the students' fact sheets and compare and contrast the two planets.
• Discuss how traveling such distances will require time and how they might try to travel this far.
Extensions
• Have students complete a Venn diagram that compares and contrasts the two planets.
• Have students draw the Sun on poster board and represent the distance between the Earth and the Sun, and Mars and the Sun, using the toilet paper as a model for the distance.
• Repeat the activity using English units, rather than metric. For practice, have students do their own conversions in preparation for that activity.

Measuring the Distance Student Page