The possibility of life on other worlds is one of enormous fascination. This book emphasizes how intelligence and culture helped humans form a civilization that now has the technology to detect and communicate with possible extraterrestrial civilizations. Topics discussed include indications and characteristics of intelligence, the evolutionary increase in the size of the human brain, survival needs, and the stages of human culture. Activities encourage students to examine the possibility of sending messages through space and the social issues related to the search for extraterrestrial intelligence and to contemplate how an extraterrestrial civilization may have evolved. Each unit includes the following: overview, concepts, skills, teacher's guide, and logbook. (JRH)