Optical Imaging Instruments and Main Science Results of Small Body Exploration: A Review

Compared with planets and their moons, small bodies retain the characteristics of their early formation. Therefore small bodies, especially Near Earth Asteroids (NEA), have become one of the most valuable targets in space exploration. This paper presents a review of the current status of small body exploration, including the science objectives, main optical imaging instruments and the main scientific results obtained from the relevant exploration missions in the past two decades. Then, it outlines and discusses future missions to small bodies by different space agencies, including those already planned and under development. Finally, it discusses the trend of optical imaging instrument development for exploring small bodies.