Methods of Studying the Solar System

Abstract

Because of the considerable brightness of some of its objects, the Solar System has been studied since antiquity. For centuries, these observations were limited to the visible region. Successive advances were due to the use, from the start of the 17th century, of larger and larger refractors and (later) reflectors, with photographic observations succeeding visual ones. Over the course of the 20th century, astronomical observational techniques underwent a genuine revolution. It saw the beginning of astronomy from space, which gained access to the ultraviolet and infrared spectral regions, and then the X-ray and γ-ray regions. It also saw the introduction of radio astronomy. Finally, for the Solar System, it saw the beginning of ‘in situ’ observations with the launch, from the 1960s onward, of spaceprobes towards the Moon and the planets. The aim of this chapter is to give an overall view of the observational techniques that have been, or still are used to study the Solar System.