A Powerful Window into Cosmic Evolution Terahertz (THz) observations of interstellar atoms, molecules, and dust serve as powerful probes of the conditions within the interstellar medium that permeates our galaxy, providing insights into the origins of stars, planets, galaxies, and the Universe. Taking a cross-disciplinary approach to the subject, Terahertz Astronomy explores THz astrophysics and the technologies that make this rapidly evolving field possible. The first four chapters of the book discuss the origin and interpretation of THz light in astrophysical sources. The remaining five chapters present an overview of the technologies used to collect and detect THz light. Every chapter contains worked-out examples and exercises. The author explains each topic as intuitively as possible and includes the equations needed for real-life astrophysical applications. In just a few years, the number of active THz researchers has substantially grown due to increased interest in terrestrial remote sensing at THz frequencies. This book provides researchers with both the background science and technology to interpret THz observations and design, build, and deploy THz astronomical instrumentation.