On August 24, 2006, a group of astronomers made a big announcement: Pluto could no longer be considered a planet. This book explains how advancements in technology have changed our understanding of the universe--and exactly how and why the number of planets in our solar system went from nine to eight.

From NPR correspondent Keith O' Brien comes this thrilling Young Readers' edition of the untold story about pioneering women, including Amelia Earhart, who fought to compete against men in the high-stakes national air races of the 1920s and 1930s--and won. In the years between World War I and World War II, airplane racing was one of the most popular sports in America. Thousands of fans flocked to multiday events, and the pilots who competed in these...