National Science Education Standards:

Content Standard B: Physical Science – Properties of objects and materials
Content Standard D: Earth and Space Science – Properties of Earth materials

This activity helps students understand why Mars is called the Red Planet.

(BACKGROUND INFORMATION)
What do we already know about water on Mars?

• The 2001 Mars Odyssey spacecraft found water on Mars.
• The Phoenix Lander will travel to Mars in 2007 to sift through Martian arctic soil. If all goes as planned, by June 2008, the Phoenix will land on a section of Mars believed to hold nearly 80% water-ice by volume in the top 50 cm of the surface.
• If we ever expect to successfully land people on the Martian surface - and even live on it - we will need either to make or find materials there to help us survive and return to Earth.

Activity - The Red Planet

paper, light-colored sand, steel wool, scissors, magnifying lens, water

Pre-Lesson Instructions:

1. Students should work in groups of two to four.

1. Review what students already know about Mars. Begin by watching the video newsbreak “What’s so cool about finding water on Mars?”
2. Discuss that Mars is the fourth planet from the Sun. Mars is the only planet whose surface can be seen in detail from the Earth. It is smaller than Earth.
3. Ask if students know why Mars is called the Red Planet? Mars is called the Red Planet because it is covered in reddish-brown rocks and soil. Most of the surface is flat, but there are several massive, extinct volcanoes. The tallest volcano, Olympus Mons, is the tallest volcano in our solar system. It's three times taller than Mt. Everest. Mars also has a gigantic canyon, Vallis Marineris. This canyon is as long as the distance from New York to San Francisco.
4. Mars has polar ice caps and clouds in its atmosphere, seasonal weather patterns, volcanoes, canyons and other recognizable features. However, conditions on Mars vary wildly from what we know on our own planet. Over the past three decades, spacecraft have shown us that Mars is rocky, cold, and sterile beneath its hazy, pink sky. We've discovered that today's Martian wasteland hints at a formerly volatile world where volcanoes once raged, meteors plowed deep craters, and flash floods rushed over the land. And, Mars continues to throw out new enticements with each landing or orbital pass made by our spacecraft.
5. Explain to the class that they’ll be running experiments to try to observe why the soil of Mars looks red.
6. Each group should fill a pan half full of sand.
7. Ask students to cut the steel wool into tiny squares and mix the pieces of steel wool with the sand.
8. Students should cover the sand with water. They need to observe the sand, discuss how it looks, and draw and color pictures of the sand. Be sure that students add the date to the drawings.
9. Ask students to check the sand every day, being sure to keep it covered in water. Students should make daily observations and record all changes.
10. At the end of the week, ask students to make final observations. Discuss the changes in the color of the sand. How does this compare to the sand of Mars? (Martian sand contains iron and oxygen. Those are the ingredients added to the sand in the experiment. When iron mixes with water and oxygen, it rusts and turns a reddish-brown. Scientists think there was once enough water on Mars that the whole planet rusted and turned red. The reddish color of the rust can be seen all the way from Earth.)

Extension:

Ask students to look for other examples of rust on Earth.