Rainbows, Halos, Coronas and Glories: Beautiful Sources of Information

Abstract

ainbows, halos, coronas, and glories are aesthetic features admired over millennia by man. They are also carriers of useful information about the physical properties of drops and solid particles floating in the atmospheres of Earth and other planets. Although atmospheric optics is a centuries-old discipline, significant progress in the understanding of these phenomena has been achieved during the past 40 years, as well as of their relation to the physical properties of the individual scatterers. At the same time, with the development of planetary exploration, the number of observations of rainbows, halos, and glories in the atmospheres of planets other than Earth is steadily growing. In this article we describe these phenomena and their information content and illustrate them with pictures mostly showing their typical appearance rather than presenting the ?best pictures ever.?