But a major part of our answer is imbedded in the physical universe. We cannot hope to find a complete answer until we understand how the birth of the universe, the origin of galaxies, the evolution of stars, and the formation of planets created and brought together the atoms of which we are made. A basic understanding of astronomy is fundamental to knowing what we are. Astronomy is exciting because it is about us. Part of the excitement of astronomy is the discovery of new things.
Astronomers expect to be astonished.
That excitement is reflected in this book in the form of new images, new discoveries, and new understandings that take us, in an introductory course, to the frontier of human knowledge. Here we explore the new evidence of an ancient ocean on Mars and a modern ocean on Jupiter's moon Europa. We will study the newest images of dying stars, and we will struggle to understand new evidence that the expansion of the universerse is speeding up. These new discoveries in astronomy are exciting because they are about us. They tell us more and more about what we are.