Although science has played an important role in answering many significant questions that concern humankind, there are also many questions that have been left unanswered—and could potentially remain that way. This volume examines many of the mysteries scientists have explained and continue to attempt to explain, including the origins and evolution of life on Earth, the possibility of life beyond Earth, the inner workings of the human mind, and seemingly inexplicable phenomena on Earth and in space. These articles are a testament to the amazing accomplishments of the scientific community in solving mysteries as well as an acknowledgment of the limits of current scientific knowledge.