JOURNEY TO THE CENTER OF THE EARTH

WHAT YOU NEED

Clay Balls
1 Compass
2 Toothpicks
Newspaper

BACKGROUND

How do geologists find out about the inside of the earth without taking a journey inside? They have many ways, some simple and some complex. Here's a very simple way of getting information about someting you can't see.

WHAT YOU DO

1. Cover your desk with newspaper to keep the clay from sticking.

2. Each clay ball has a common object inside. Try to find out what's inside without breaking open the clay. Before you start, discuss possible techniques with your team or class.

3. Stick a toothpick in. Is the object inside hard or soft?

4. Stick the toothpick in at several different places. Can you figure outthe shape of the object?

5. Put the compass flat on the desk. Slowly move the ball around the compass. If the compass needle moves, the ball contains an object that is magnetic.

6. Use all of the clues you can collect to try to guess what the object is.

BALL OBSERVATIONS & REASONS OBJECT