Retrieving the Core

1. Start by reviewing the inside of the Earth and it’s layers. Questions you might ask are:
   1. What are the layers inside of the Earth called? (crust, mantle, outer core, inner core)
   2. What is the crust made of? Who can name the 3 types of rock found their? (igneous, metamorphic, sedimentary)
   3. Who can tell me about the mantle? The core?
2. Read The Magic School Bus: Inside the Earth to the students to facilitate discussion on the layers of the Earth and connect to previous activities.
3. Discuss the core of the Earth, explaining the difference between the outer core and inner core. Review what the children know about magnets.
4. Divide the class into groups of 2 students. Explain that they will use the “School Bus” they made in lesson 1 (the NXT vehicle) for this challenge.
5. Tell the students that the design challenge is to build and program your “School Bus” to collect a magnetic sample from the core of the Earth.
6. Write the challenge on the board:
   1. Using the model of the core, explain that the NXT car must travel to the core.
   2. Once in the inner core, the collecting invention must collect a sample from the core.
7. Explain to students that they will be allowed to use another motor for this challenge.
8. Brainstorm some ideas of what might work to retrieve the rock sample. Write ideas on the board for future reference.
9. Distribute the “Engineering Design Sheet” (attached) to each student.
10. Model how to fill out these worksheets. Let the students complete their designs before they can begin to build.
11. Allow students to build their inventions.

Note: If this lesson is going to be taught in 2 class periods, this is a good time to stop.

1. If possible, bring up MINDSTORMS on a computer and mirror it on a TV monitor so that all the students can see. If not, model it to a few students at a time around a computer.
2. Have each student fill out an “Engineer’s Programming Sheet” (attached) to complete before they program their NXT. Students can cut an paste icons from the “Programmer’s Icon Sheet” on to the programming sheet.
3. When students have finished planning, let them program on MINDSTORMS and download their program to their NXTs.
4. Allow students to test their designs on the model Earth (examples of model Earths are attached).
5. Bring the class together. Let each group demonstrate their design. When all the groups have had a chance to show their design, review today’s activity:
   1. What were some difficulties that students encountered while building? How did they overcome these difficulties?
   2. What were some difficulties that students encountered while programming? How did students fix their programs?
   3. Did any students have to redesign?
   4. Review the layers of the Earth.