Development and prospect of planetary optical remote sensing at Lenghu

Planetary science is the one among the frontiers of science in the world and also is one of the key components of the development strategy of science and technology in China, which reflects the state of national natural science and the comprehensive national strength. Planetary science is the scientific study of the fundamental characteristics of planets, moons, and comets in the inner and outer of the solar system as well as their formation and evolution processes. Planetary science research mainly depends on deep space exploration, and it is highly interdisplinary and was built from Earth science, space science, and astronomy. Planetary space, a critical region of mass and energy exchange between the planet and the interplanetary space, is an integral part of the planetary multi-layer coupling system. Atmospheres of different compositions and plasmas of different densities and energies exist in planetary space, where mass transportation at different temporal and spatial scales and various energy deposition and dissipation processes occur. These processes are driven by the changes in the solar wind and the internal driving forces of the planet. Knowledge pertaining to the global mass and energy transportation in planetary space is essential to investigate the mass escape from the planets and the evolution of planetary environment. Optical remote sensing overcomes the difficulties of capturing global views and distinguishing spatiotemporal variations in in-situ particle and field detections. Especially, as characterized by low-cost, maintainability, long-term observations and fast responses, the ground-based optical remote sensing provides important data for scientific research. This paper introduces the principles and applications of optical remote sensing in planetary sciences. Then, the first ground-based planetary observatory in China, the Lenghu Observatory for Planetary Sciences, established by the Institute of Geology and Geophysics, Chinese Academy of Sciences, will be introduced in detail. The future development of the observatory will also be discussed.