Rapid Formation of Ice Giant Planets
نویسنده
چکیده
The existence of Uranus and Neptune presents severe difficulties for the core accretion model for the formation of ice giant planets. We suggest an alternative mechanism, namely disk instability leading to the formation of gas giant protoplanets, coagulation and settling of dust grains to form ice/rock cores at their centers, and photoevaporation of their gaseous envelopes by a nearby OB star, as a possible means of forming ice giant planets.
منابع مشابه
Formation of the Giant Planets?
Observational constraints on interior models of the giant planets indicate that these planets were all much hotter when they formed and they all have rock and/or ice cores of ten to thirty earth masses. These cores are probably soluble in the envelopes above, especially in Jupiter and Saturn, and are therefore likely to be primordial. They persist despite the continual upward mixing by thermall...
متن کاملModels of the Collisional Damping Scenario for Ice Giant Planets and Kuiper Belt Formation
Chiang et al. (2006, hereafter C06) have recently proposed that the observed structure of the Kuiper belt could be the result of a dynamical instability of a system of ∼5 primordial ice giant planets in the outer Solar System. According to this scenario, before the instability occurred, these giants were growing in a highly collisionally damped environment according to the arguments in Goldreic...
متن کاملOuter Irregular Satellites of the Planets and Their Relationship with Asteroids, Comets and Kuiper Belt Objects
Outer satellites of the planets have distant, eccentric orbits that can be highly inclined or even retrograde relative to the equatorial planes of their planets. These irregular orbits cannot have formed by circumplanetary accretion and are likely products of early capture from heliocentric orbit. The irregular satellites may be the only small bodies remaining which are still relatively near th...
متن کاملRapid Formation of Icy Super-Earths and the Cores of Gas Giant Planets
We describe a coagulation model that leads to the rapid formation of superEarths and the cores of gas giant planets. Interaction of collision fragments with the gaseous disk is the crucial element of this model. The gas entrains small collision fragments, which rapidly settle to the disk midplane. Protoplanets accrete the fragments and grow to masses & 1 M⊕ in ∼ 1 Myr. Our model explains the ma...
متن کاملImplications of the Giant Planets 75 IMPLICATIONS OF THE GIANT PLANETS FOR THE FORMATION AND EVOLUTION OF PLANETARY SYSTEMS
The giant planet region in our Solar System appears to be bounded inside by the limit of water condensation, suggesting that the most abundant astrophysical condensate plays an important role in giant planet formation. Indeed, Jupiter and Saturn exhibi~ evidence for rock and/or ice cores or central concentrations that probably accumulated first, acting as nuclei for subsequent gas accumulation....
متن کامل