Origin of the orbital architecture of the giant planets of the Solar System

Abstract

Planetary formation theories suggest that the giant planets formed on circular and coplanar orbits. The eccentricities of Jupiter, Saturn and Uranus, however, reach values of 6 per cent, 9 per cent and 8 per cent, respectively. In addition, the inclinations of the orbital planes of Saturn, Uranus and Neptune take maximum values of approximately 2 degrees with respect to the mean orbital plane of Jupiter. Existing models for the excitation of the eccentricity of extrasolar giant planets have not been successfully applied to the Solar System. Here we show that a planetary system with initial quasi-circular, coplanar orbits would have evolved to the current orbital configuration, provided that Jupiter and Saturn crossed their 1:2 orbital resonance. We show that this resonance crossing could have occurred as the giant planets migrated owing to their interaction with a disk of planetesimals. Our model reproduces all the important characteristics of the giant planets' orbits, namely their final semimajor axes, eccentricities and mutual inclinations.

Tidal Venuses: Triggering a Climate Catastrophe via Tidal Heating

“…Several scenarios suggest that fully formed planets can be Tidal Venuses. Orbital instabilities can excite e. Planet-planet scattering and divergent resonance crossing appear to play a role in sculpting many planetary systems, including our own (e.g., Weidenschilling and Marzari, 1996;Tsiganis et al, 2005;Nesvorný, 2011).…”

Water on Planets

“…Recently it has been proposed that outer main belt and outer solar system asteroids (large compared to comet nuclei, and hydrated because of their formation beyond the snow line) could have been 38 J. F Bell III significant sources of Earth's water during and shortly after accretion. More specifically, the hypothesized migration of the giant planets during the early history of the solar system has been invoked as a source of substantial dynamical mixing/scattering of small bodies from the outer solar system to the inner solar system, and as a potential explanation for the late heavy bombardment of the Earth-Moon system that is preserved in the lunar impact record (e.g., Tsiganis et al, 2005;Morbidelli et al, 2005). In this so-called "Nice model" of solar system evolution, the orbits of many small outer solar system objects could have been dramatically altered when Jupiter and Saturn passed through a 2:1 mean-motion resonance around ∼ 4 Ga, scattering relatively large, volatile-rich bodies into the inner solar system (as well as the Kuiper Belt) and providing potential large-impact sources of water for the terrestrial planets.…”

“…Whether or not D-type and Trojan asteroids represent a significant reservoir of water is an unresolved question that could require future up-close spacecraft missions to resolve. Given the dynamical importance of the Trojans, in particular, as "trapped" examples of potentially once more distant objects scattered into the inner solar system by the migration of the giant planets (e.g., Tsiganis et al, 2005;Morbidelli et al, 2005), understanding their composition could provide significant insights about the role of external delivery of water to Earth and the other terrestrial planets (see also §4.1).…”

Formation of brown dwarfs and planets

“…The core accretion scenario has problems creating even Jupiter and Saturn in a time short enough to also allow rocky planets to form without migrating into the Sun (Morishima et al 2010), and Uranus and Neptune are required to initially form in close proximity to Jupiter and Saturn and to subsequently migrate to their present locations (Tsiganis et al 2005). While this is in principle a possible work-around in the particular cases of Uranus and Neptune there are many other gas and ice giants discovered in exoplanetary systems, some at considerable distances from their host stars (sometimes of low mass), thus further aggravating the problems with time scales in the core accretion scenario.…”