The Kuiper Belt and its Primordial Sculpting

Abstract

We discuss the structure of the Kuiper belt as it can be inferred from the first decade of observations. In particular, we focus on its most intriguing properties – the mass deficit, inclination distribution, the apparent existence of an outer edge and of a correlation among inclinations, colours and sizes – which clearly show that the belt has lost its pristine structure of a dynamically cold protoplanetary disk. Understanding how the Kuiper belt acquired its present structure will provide insight into the formation of the outer planetary system and on its early evolution. We outline a scenario of primordial sculpting – issued from a combination of mechanisms proposed by various authors – that seems to explain most of the observed properties of the Kuiper belt. Several aspects are not yet totally clear. But, for the first time, we have a view – if not of the detailed sculpture – at least of its rough cast.