COMPARATIVE MODELS OF URANUS AND NEPTUNE

Models of Uranus and Neptune are computed based on the assumption that these planets consist of three layers: a rock core, an ice shell, and an atmosphere. Uranus models require that the ice shell have a densit y some 10% lower than the canonical density for an ice mixture. Two Ne ptune models:are found, one with the canonical density in the ice shel l, and one with a density 20% lower. The implications of these models are discussed.