Planetary obliquities / Dr Melaine Saillenfest (Paris Observatory)

Abstract: Our origins -- how the Solar System has formed and evolved to its observed state -- is one of the main focuses of modern astronomy. The orbits of Solar System planets (which are approximately circular and coplanar) are well known signatures of the processes at work during the early stages of the Solar System evolution. Other key signatures are the inclinations of the planets' spin axes, or "obliquities". In this colloquium, I will review the evolution mechanisms of planetary obliquities. I will show how recent discoveries modify our understanding of the history of giant planets and their moons, in the Solar System and beyond.