Our modern understanding of the heliocentric universe developed five hundred years ago. Since the time of Copernicus and Galileo, scientists have made major strides in understanding how gravity, stars, and planets interact. Gravity, Orbiting Objects, and Planetary Motion explains how early ideas have given way to sophisticated, proven theories about the universe. The book aligns with Next Generation Science Standards and also presents a look at what is next in the cutting-edge field of astronomy.