On the formation of the outer satellite groups of Jupiter

Colombo, G.; Franklin, F. A.

doi:10.1016/0019-1035(71)90073-x

Cited by 83 publications

(82 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It has been suggested that irregular satellites were captured from heliocentric orbits (1) via dissipation of their orbital energy by gas drag (Pollack et al 1979;Ć uk & Burns 2004;Kortenkamp 2005), (2) by collisions between planetesimals (Colombo & Franklin 1971), or (3) by so-called pull-down capture, in which the planet's gradual growth leads to a capture of objects from the 1:1 mean motion resonance with the planet (Heppenheimer & Porco 1977). …”

Section: Introductionmentioning

confidence: 99%

Capture of Irregular Satellites during Planetary Encounters

2007

View full text Add to dashboard Cite

More than 90 irregular moons of the Jovian planets have recently been discovered. These moons are an enigmatic part of the solar system inventory. Their origin, which is intimately linked with the origin of the planets themselves, has yet to be adequately explained. Here we investigate the possibility that the irregular moons were captured from the circumsolar planetesimal disk by three-body gravitational reactions. These reactions may have been a frequent occurrence during the time when the outer planets migrated within the planetesimal disk. We propose a new model for the origin of irregular satellites in which these objects are captured from the planetesimal disk during encounters between the outer planets themselves in the model for outer planet migration advocated by Tsiganis and collaborators. Through a series of numerical simulations we show that nearby planetesimals can be deflected into planet-bound orbits during close encounters between planets, and that the overall efficiency of this capture process is large enough to produce populations of observed irregular satellites at Saturn, Uranus, and Neptune. The orbits of captured objects are broadly similar to those of known distant satellites. Jupiter, which typically does not have close encounters with other planets in the model of Tsiganis and coworkers, must have acquired its irregular satellites by a different mechanism. Alternatively, the migration model should be modified to accommodate Jupiter's encounters. Moreover, we find that the original size-frequency distribution of the irregular moons must have significantly evolved by collisions to produce their present populations. Our new model may also provide a plausible explanation for the origin of Neptune's large moon Triton.

show abstract

Section: Introductionmentioning

confidence: 99%

Capture of Irregular Satellites during Planetary Encounters

2007

View full text Add to dashboard Cite

show abstract

“…This mechanism, the so-called break-up process, leads to the formation of dynamical groupings (e.g. Colombo & Franklin 1971;Nesvorny et al 2004). After a break-up the resulting fragments of each progenitor form a population of irregular satellites with similar surface composition, i.e.…”

Section: Their Origin: How and When Irregular Satellites Of Giant Plamentioning

confidence: 99%

Last giant impact on the Neptunian system

Parisi

Valle

2011

A&A

View full text Add to dashboard Cite

Context. Current models of the formation of ice giants attempt to account for the formation of Uranus and Neptune within the protoplanetary disk lifetime. Many of these models calculate the formation of Uranus and Neptune in a disk that may be several times the minimum mass solar nebula model (MMSN). Modern core accretion theories assume the formation of the ice giants either in situ, or between ∼10-20 AU in the framework of the Nice model. However, at present, none of these models account for the spin properties of the ice giants. Aims. Stochastic impacts by large bodies are, at present, the usually accepted mechanisms able to account for the obliquity of the ice giants. We attempt to set constraints on giant impacts as the cause of Neptune's current obliquity in the framework of modern theories. We also use the present orbital properties of the Neptunian irregular satellites (with the exception of Triton) to set constraints on the scenario of giant impacts at the end of Neptune formation. Methods. Since stochastic collisions among embryos are assumed to occur beyond oligarchy, we model the angular momentum transfer to proto-Neptune and the impulse transfer to its irregular satellites by the last stochastic collision (GC) between the protoplanet and an oligarchic mass at the end of Neptune's formation. We assume a minimum oligarchic mass m i of 1 m ⊕ . Results. From angular momentum considerations, we obtain that an oligarchic mass m i ∼ 1 m ⊕ ≤ m i ≤ 4 m ⊕ would be required at the GC to reproduce the present rotational properties of Neptune. An impact with m i > 4 m ⊕ is not possible, unless the impact parameter of the collision were very small. This result is invariant either Neptune had formed in situ or between 10-20 AU and does not depend on the occurrence of the GC after or during the possible migration of the planet. From impulse considerations, we find that an oligarchic mass m i ∼ 1 m ⊕ ≤ m i ≤ 1.4 m ⊕ at the GC is required to keep or capture the present population of irregular satellites. If m i had been higher, the present Neptunian irregular satellites had to be formed or captured after the end of stochastic impacts. Conclusions. The upper bounds on the oligarchic masses (4 m ⊕ from the obliquity of Neptune and 1.4 m ⊕ from the Neptunian irregular satellites) are independent of unknown parameters, such as the mass and distribution of the planetesimals, the location at which Uranus and Neptune were formed, the Solar Nebula initial surface mass density, and the growth regime. If stochastic impacts had occurred, these results should be understood as upper constraints on the oligarchic masses in the trans-Saturnian region at the end of ice planet formation and may be used to set constraints on planetary formation scenarios.

show abstract

“…Finally, a third well identified mechanism of capture could be from the collision or collisionless interaction of two small bodies within the Hill sphere of the planet (Colombo & Franklin;Tsui 2000;Astakhov et al 2003;Funato et al 2004;Agnor & Hamilton 2004). This could occur as asteroid-asteroid or asteroid-satellite encounters.…”

Section: Capture Through Collisional or Collisionless Interactionsmentioning

confidence: 99%

Outer irregular satellites of the planets and their relationship with asteroids, comets and Kuiper Belt objects

Sheppard

2005

Proc. IAU

View full text Add to dashboard Cite

Abstract. 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 their formation locations within the giant planet region. The study of the irregular satellites provides a unique window on processes operating in the young solar system and allows us to probe possible planet formation mechanisms and the composition of the solar nebula between the rocky objects in the main asteroid belt and the very volatile rich objects in the Kuiper Belt. The gas and ice giant planets all appear to have very similar irregular satellite systems irrespective of their mass or formation timescales and mechanisms. Water ice has been detected on some of the outer satellites of Saturn and Neptune whereas none has been observed on Jupiter's outer satellites.

show abstract

On the formation of the outer satellite groups of Jupiter

Cited by 83 publications

References 2 publications

Capture of Irregular Satellites during Planetary Encounters

Capture of Irregular Satellites during Planetary Encounters

Last giant impact on the Neptunian system

Outer irregular satellites of the planets and their relationship with asteroids, comets and Kuiper Belt objects

Contact Info

Product

Resources

About