The Planetary Science Institute is a private, nonprofit 501(c)(3) corporation dedicated to Solar System exploration. It is headquartered in Tucson, Arizona, where it was founded in 1972.
PSI scientist are involved in numerous NASA and international missions, the study of Mars and other planets, the Moon, asteroids, comets, interplanetary dust, impact physics, the origin of the solar system, extra-solar planet formation, dynamics, the rise of life, and other areas of research. They conduct fieldwork on all continents of the Earth. They are also actively involved in science education and public outreach though school programs, children's books, popular science books and art.
PSI scientists are based in 20 states and the District of Columbia, Australia, Canada, France, Germany, Ireland, Latvia, Russia, South Africa, Switzerland and the United Kingdom.