This is the first collegiate-level textbook to comprehensively cover the Search for Extraterrestrial Intelligence (SETI), addressing its theoretical, practical, historical, and social aspects. It explores the nature of alien life, technosignatures, detection methods, and SETI's place in society and culture. Topics include the Fermi Paradox, Drake Equation, METI, post-detection protocols, and ethical considerations. The book aims to establish SETI as a formal scientific discipline, with defined terminology and literature. Designed for upper-level astronomy undergraduates or astrobiology graduate students, it includes problem sets and extensive references for further study. It is suitable for students in astronomy, biology, geophysics, and related fields.

Key features: * Written by a leading researcher in the field * Provides a broad, interdisciplinary approach * Based on the successful SETI courses at Penn State * Flexible assignments and identification of key primary sources allows adaptation for advanced undergraduates, graduate students, and even non-astronomy students in related fields