Infrared remote sensing of planetary surfaces: an overview, outstanding questions, and prospects

Abstract

We owe a major part of our knowledge about surface composition and structure of solid planetary surfaces to infrared imaging and Fourier transform spectroscopy. Based on these methods, it succeeds to observe single planetary objects in a global geo-scientific content. The topics of infrared surface studies are mineralogical composition analyses, measurement of surface temperature, thermal inertia, and photometric observation of surface regolith texture. The comparison of infrared with photogeologic data forms the essential basis for comparative studies in planetology. The present paper summarizes outstanding results by examples of ESA experiments like VIRTIS on Venus Express and Rosetta, PFS on Mars Express, MERTIS on Bepi Colombo, and TIRVIM on ExoMars, and provides an outlook for future plans. The instruments are described, and the interplay of disciplines like planetology, IR measuring techniques, and space flight engineering is demonstrated. Infrared remote sensing provides essential knowledge about the current state of solid planetary surfaces. This allows studying fundamental questions in comparative planetology.