Space and planetary geology comprises that branch of the discipline of geology that applies basic scientific principles to the study of the origin, development, and characteristics of solar system objects such as planets, satellites, asteroids, comets, meteorites, and interplanetary dust particles. On Earth, space and planetary geology investigations are generally limited to impact craters and impact effects upon Earth, and to the study of Earth as an analogue for other planets and their processes. As technology progresses in the future, the field of space and planetary geology will likely expand to include extra-solar system objects as well. Space and planetary geology is also called astrogeology.

Astronauts sleeping in freefall. Experiencing weightlessness over prolonged periods of time can produce detrimental physiological effects. U.S. National Aeronautics and Space Administration (NASA).

Space and planetary geology has it origins in telescopic observations of planets, satellites...