Dynamics of the Giant Planets of the Solar System in the Gaseous Protoplanetary Disk and Their Relationship to the Current Orbital Architecture

AbstractThe “Grand Tack” model proposes that the inner Solar System was sculpted by the giant planets' orbital migration in the gaseous protoplanetary disk. Jupiter first migrated inward then Jupiter and Saturn migrated back outward together. If Jupiter's turnaround or “tack” point was at ~ 1.5 AU the inner disk of terrestrial building blocks would have been truncated at ~ 1 AU, naturally producing the terrestrial planets' masses and spacing. During the gas giants' migration the asteroid belt is severely depleted but repopulated by distinct planetesimal reservoirs that can be associated with the present-day S and C types. The giant planets' orbits are consistent with the later evolution of the outer Solar System.Here we confront common criticisms of the Grand Tack model. We show that some uncertainties remain regarding the Tack mechanism itself; the most critical unknown is the timing and rate of gas accretion onto Saturn and Jupiter. Current isotopic and compositional measurements of Solar System bodies – including the D/H ratios of Saturn's satellites – do not refute the model. We discuss how alternate models for the formation of the terrestrial planets each suffer from an internal inconsistency and/or place a strong and very specific requirement on the properties of the protoplanetary disk.We conclude that the Grand Tack model remains viable and consistent with our current understanding of planet formation. Nonetheless, we encourage additional tests of the Grand Tack as well as the construction of alternate models.

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The partitioning of the inner and outer solar system by a structured protoplanetary disk

10.5194/egusphere-egu2020-3685 ◽

2020 ◽

Author(s):

Ramon Brasser ◽

Stephen Mojzsis

Keyword(s):

Solar System ◽

Protoplanetary Disk ◽

Giant Planets ◽

Iron Meteorites ◽

Effective Barrier ◽

Dynamical Simulations ◽

Pressure Maximum ◽

Ringed Structure ◽

Isotopic Anomalies ◽

Multiple Rings

Mass-independent isotopic anomalies in planets and meteorites define two cosmochemically distinct regions: the carbonaceous and non-carbonaceous meteorites, implying that the non-carbonaceous (terrestrial) and carbonaceous (jovian) reservoirs were kept separate during and after planet formation. The iron meteorites show a similar dichotomy.The formation of Jupiter is widely invoked to explain this compositional dichotomy by acting as an effective barrier between the two reservoirs. Jupiter&#8217;s solid kernel possibly grew to ~20 Mearth in ~1 Myr from the accretion of sub meter-sized objects (termed &#8220;pebbles&#8221;), followed by slower accretion via planetesimals. Subsequent gas envelope contraction is thought to have led to Jupiter&#8217;s formation as a gas giant.We show using dynamical simulations that the growth of Jupiter from pebble accretion is not fast enough to be responsible for the inferred separation of the terrestrial and jovian reservoirs. We propose instead that the dichotomy was caused by a pressure maximum in the disk near Jupiter&#8217;s location, which created a ringed structure such as those detected by the Atacama Large Millimeter/submillimeter Array(ALMA). One or multiple such long-lived pressure maxima almost completely prevented pebbles from the jovian region reaching the terrestrial zone, maintaining a compositional partition between the two regions. We thus suggest that our young solar system&#8217;s protoplanetary disk developed at least one and likely multiple rings, which potentially triggered the formation of the giant planets [1]. [1] Brasser, R. and Mojzsis, S.J. (2020) Nature Astronomy doi: 10.1038/s41550-019-0978-6

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The Long View of Planetary Systems

10.1093/oso/9780198799894.003.0011 ◽

2018 ◽

Author(s):

Karel Schrijver

Keyword(s):

Solar System ◽

Milky Way ◽

Planetary Systems ◽

Giant Planets ◽

Milky Way Galaxy ◽

Population Statistics ◽

The Past ◽

General Terms ◽

The Galaxy ◽

The Universe

How many planetary systems formed before our’s did, and how many will form after? How old is the average exoplanet in the Galaxy? When did the earliest planets start forming? How different are the ages of terrestrial and giant planets? And, ultimately, what will the fate be of our Solar System, of the Milky Way Galaxy, and of the Universe around us? We cannot know the fate of individual exoplanets with great certainty, but based on population statistics this chapter sketches the past, present, and future of exoworlds and of our Earth in general terms.

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In Situ exploration of the giant planets

Experimental Astronomy ◽

10.1007/s10686-021-09775-z ◽

2021 ◽

Author(s):

O. Mousis ◽

D. H. Atkinson ◽

R. Ambrosi ◽

S. Atreya ◽

D. Banfield ◽

...

Keyword(s):

Solar System ◽

Giant Planets ◽

Atmospheric Composition ◽

Formation History ◽

History Of ◽

Composition Structure ◽

Galileo Probe ◽

Probe Measurements

AbstractRemote sensing observations suffer significant limitations when used to study the bulk atmospheric composition of the giant planets of our Solar System. This impacts our knowledge of the formation of these planets and the physics of their atmospheres. A remarkable example of the superiority of in situ probe measurements was illustrated by the exploration of Jupiter, where key measurements such as the determination of the noble gases’ abundances and the precise measurement of the helium mixing ratio were only made available through in situ measurements by the Galileo probe. Here we describe the main scientific goals to be addressed by the future in situ exploration of Saturn, Uranus, and Neptune, placing the Galileo probe exploration of Jupiter in a broader context. An atmospheric entry probe targeting the 10-bar level would yield insight into two broad themes: i) the formation history of the giant planets and that of the Solar System, and ii) the processes at play in planetary atmospheres. The probe would descend under parachute to measure composition, structure, and dynamics, with data returned to Earth using a Carrier Relay Spacecraft as a relay station. An atmospheric probe could represent a significant ESA contribution to a future NASA New Frontiers or flagship mission to be launched toward Saturn, Uranus, and/or Neptune.

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The comparative exploration of the ice giant planets with twin spacecraft: Unveiling the history of our Solar System

Planetary and Space Science ◽

10.1016/j.pss.2014.09.005 ◽

2014 ◽

Vol 104 ◽

pp. 93-107 ◽

Cited By ~ 19

Author(s):

Diego Turrini ◽

Romolo Politi ◽

Roberto Peron ◽

Davide Grassi ◽

Christina Plainaki ◽

...

Keyword(s):

Solar System ◽

Giant Planets ◽

History Of

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Chemistry of the Solar System Revealed in the Interiors of the Giant Planets

Proceedings of the International Astronomical Union ◽

10.1017/s1743921311025026 ◽

2011 ◽

Vol 7 (S280) ◽

pp. 249-260 ◽

Cited By ~ 1

Author(s):

Jonathan I. Lunine

Keyword(s):

Solar System ◽

Microwave Radiometer ◽

Giant Planets ◽

Isotopic Ratios ◽

Data Sets ◽

Terrestrial Water ◽

Galileo Probe ◽

Probe Mission ◽

Juno Mission

AbstractThe giant planets of our solar system contain a record of elemental and isotopic ratios of keen interest for what they tell us about the origin of the planets and in particular the volatile compositions of the solid phases. In situ measurements of the Jovian atmosphere performed by the Galileo Probe during its descent in 1995 demonstrate the unique value of such a record, but limited currently by the unknown abundance of oxygen in the interior of Jupiter–a gap planned to be filled by the Juno mission set to arrive at Jupiter in July of 2016. Our lack of knowledge of the oxygen abundance allows for a number of models for the Jovian interior with a range of C/O ratios. The implications for the origin of terrestrial water are briefly discussed. The complementary data sets for Saturn may be obtained by a series of very close, nearly polar orbits, at the end of the Cassini-Huygens mission in 2016-2017, and the proposed Saturn Probe. This set can only obtain what we have for Jupiter if the Saturn Probe mission carries a microwave radiometer.

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New Results on the Composition of the Outer Planets and Titan

Highlights of Astronomy ◽

10.1017/s1539299600017421 ◽

2005 ◽

Vol 13 ◽

pp. 891-893

Author(s):

Thierry Fouchet

Keyword(s):

Solar System ◽

Atmospheric Chemistry ◽

Recent Progress ◽

Giant Planets ◽

Atmospheric Composition ◽

Solar System Formation ◽

Outer Planets ◽

System Formation ◽

The Impact

AbstractIn this brief summary, I present recent progress on our knowledge of the Giant Planets and Titan atmospheric composition, as well as the impact of this progress on our understanding of Solar System formation, and atmospheric chemistry.

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Tracing the Origins of the Ice Giants through Noble Gas Isotopic Composition

10.5194/egusphere-egu21-7798 ◽

2021 ◽

Author(s):

Kathleen Mandt ◽

Olivier Mousis ◽

Jonathan Lunine ◽

Bernard Marty ◽

Thomas Smith ◽

...

Keyword(s):

Solar System ◽

Isotopic Composition ◽

Heavy Element ◽

Noble Gas ◽

Giant Planet ◽

Isotope Ratios ◽

Building Blocks ◽

Giant Planets ◽

Element Abundances ◽

Current State

The current composition of giant planet atmospheres provides information on how such planets formed, and on the origin of the solid building blocks that contributed to their formation. Noble gas abundances and their isotope ratios are among the most valuable pieces of evidence for tracing the origin of the materials from which the giant planets formed. In this review we first outline the current state of knowledge for heavy element abundances in the giant planets and explain what is currently understood about the reservoirs of icy building blocks that could have contributed to the formation of the Ice Giants. We then outline how noble gas isotope ratios have provided details on the original sources of noble gases in various materials throughout the solar system. We follow this with a discussion on how noble gases are trapped in ice and rock that later became the building blocks for the giant planets and how the heavy element abundances could have been locally enriched in the protosolar nebula. We then provide a review of the current state of knowledge of noble gas abundances and isotope ratios in various solar system reservoirs, and discuss measurements needed to understand the origin of the ice giants. Finally, we outline how formation and interior evolution will influence the noble gas abundances and isotope ratios observed in the ice giants today. Measurements that a future atmospheric probe will need to make include (1) the 3He/4He isotope ratio to help constrain the protosolar D/H and 3He/4He; (2) the 20Ne/22Ne and 21Ne/22Ne to separate primordial noble gas reservoirs similar to the approach used in studying meteorites; (3) the Kr/Ar and Xe/Ar to determine if the building blocks were Jupiter-like or similar to 67P/C-G and Chondrites; (4) the krypton isotope ratios for the first giant planet observations of these isotopes; and (5) the xenon isotopes for comparison with the wide range of values represented by solar system reservoirs.Mandt, K. E., Mousis, O., Lunine, J., Marty, B., Smith, T., Luspay-Kuti, A., & Aguichine, A. (2020). Tracing the origins of the ice giants through noble gas isotopic composition. Space Science Reviews, 216(5), 1-37.

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Worlds of Gas and Ice

From Dust to Life ◽

10.23943/princeton/9780691175706.003.0012 ◽

2017 ◽

Author(s):

John Chambers ◽

Jacqueline Mitton

Keyword(s):

Solar System ◽

Solid Surface ◽

Outer Part ◽

Giant Planets

This chapter focuses on the giants of the solar system. Astronomers know somewhat less about the giant planets—except Jupiter—since no probes have gone down through their atmospheres and examined them directly. However, remote observations show that they have much in common with Jupiter. The low densities of all four giants mean they are mostly made of much lighter stuff than their terrestrial cousins. As on Jupiter, most of this bulk is gaseous in the outer layers but must be compressed into liquids in the interior. None of the giants has a solid surface, and the transition between gas and liquid is not a sharp one. Astronomers refer to the outer part of the fluid envelope as the atmosphere, although the depth of the base of the atmosphere is rather arbitrary.

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3. Beautiful theories, ugly facts

10.1093/actrade/9780198841128.003.0003 ◽

2021 ◽

pp. 31-46

Author(s):

Raymond T. Pierrehumbert

Keyword(s):

Angular Momentum ◽

Solar System ◽

Planetary Systems ◽

Protoplanetary Disk ◽

Newtonian Gravity ◽

The Sun ◽

French Mathematician ◽

Modern Form

‘Beautiful theories, ugly facts’ evaluates the theories on planetary systems, particularly the Solar System. In 1734, the Swedish polymath Emmanuel Swedenborg proposed that the Sun and all the planets condensed out of the same ball of gas, in what is probably the earliest statement of the nebular hypothesis. The nebular hypothesis entered something close to its modern form in the hands of the French mathematician Pierre-Simon Laplace, who in 1796 made the clear connection to Newtonian gravity. The angular momentum problem and the structure of a protoplanetary disk, the formation of rocky cores, and the gravitational accretion of gas in the disk also come under this topic.

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