Where did we come from? Before there was life there had to be something to live on - a planet, a solar system. During the past 200 years, astronomers and geologists have developed and tested several different theories about the origin of the solar system and the nature of the Earth. Did the Earth and other planets form as a byproduct of a natural process that formed the Sun? Did the solar system come into being as the result of a catastrophic encounter of two stars? Together, the three volumes that make up A History of Modern Planetary Physics present a survey of these theories. Nebulous Earth follows the development of Laplace’s Nebular Hypothesis, its connection with ideas about the interior of the Earth, and its role in the establishment of the ‘evolutionary’ worldview that dominated science in the latter part of the nineteenth century. Brush also explores Saturn’s rings, Poincaré’s contributions to ideas about cosmic evolution, the use of seismology to probe the Earth’s core, and explanations of the Earth’s magnetic field.