A major surprise of the Apollo Moon missions was the deleterious impact of lunar dust on the astronauts, their spacesuits and other equipment, and even inside the Command/Service Module during their return to Earth. Lunar dust permeated everything and impacted mechanical systems. The dust on the Moon's surface was disturbed and became airborne by the routine actions of the astronauts as they walked and performed their exploration of the lunar surface. Over the last decade, as NASA's plans for the human exploration of Mars have developed and matured, a major concern has been the possible negative impacts of Mars surface and atmospheric dust on human health and on the human surface systems and surface operations on the Red Planet. In this book, 41 Mars scientists, mission engineers and planners and medical researchers have reviewed our current understanding and identified the knowledge gaps in a wide range of areas, including the chemical, physical and electrical properties of Mars atmospheric dust; the evolution and occurrence of localized, regional and planetary-scale dust storms; the human health effects of Mars atmospheric dust, including inhalation of and potential toxicity of dust particles; and the impact of Mars atmospheric dust on surface systems and on surface operations, among others.