Why do some planets have volcanoes on them?
How can we tell that Mercury has shrunk over time?
What happens to a space probe when it passes a planet?
Find out the answers to these questions and much more in this fascinating look at the inner planets! Read about mankind's quest to understand more about our planetary neighbours in the solar system. And through various hands-on activities and problem-solving exercises you can learn how to solve difficult questions about the inner planets in the way that astronauts and scientists do.