Drs. Brandt and Chapman provide a comprehensive introduction to comets by consolidating in one text information from the fields of history, physics, astronomy, and space science. Comets have intrigued man since ancient times, when astronomical phenomena were interpreted as evidence of divine intervention in human affairs. Today, attention to the behaviour of comets remains strong, although interest is now more specific than theological. Aided by increased technology, many space scientists look to the return of Halley's Comet in 1985-6 with the expectation that spacecraft might be sent to intercept the comet and take measurements in situ. The authors trace the historical development of investigations into the nature of comets, in addition to presenting an up-to-date account of cometary research.