Philosophical problems fundamentally infuse the theory and practice of astronomy. Bringing together fifteen historians, eleven philosophers, and four pioneering scientists, this volume provides a rigorous yet largely accessible examination of the conceptual and methodological challenges that lie at the intersection of philosophy and astronomy – broadly construed to include astrophysics, cosmology, space science, and astrobiology. Drawing largely on interdisciplinary advances from the past two centuries, the book's chapters tackle metaphysical inquiries into the fundamental nature of reality, the limits of reasoning, the problematic nature of observation and inference, the role of technology, and the epistemology of concepts such as space, time, life, and intelligence. Discussions are anchored to fascinating theories and examples from the 'canals' of Mars to exoplanets, black holes, dark matter, and the multiverse. Written primarily for practicing scientists, this volume will also serve historians and philosophers of science, as well as the curious general reader.