Letters of Intent received in 2015

LoI 2017-265
Atmospheres and Interiors of Jupiter/Saturn and Jupiter-like Exoplanets

Date:	25 October 2017 to 29 October 2017
Category:	Non-GA Symposium
Location:	Macau, AA-Country unknown
Contact:	Keke Zhang (kzhang@ex.ac.uk)
Coordinating division:	Division F Planetary Systems and Astrobiology
Other divisions:
Co-Chairs of SOC:	David Stevenson (Caltech)
	Gerald Schubert (UCLA)
	Tristan Guillot (OCA)
	Peter Read (Oxford)
	Keke Zhang (Exeter)
Co-Chairs of LOC:	Kwing Chan (MUST, Macau)
	Aoao Xu (MUST, Macau)
	Jianghhui Ji (PMO)
	Bao Mei (MUST, Macau)
	Dongdong Ni (MUST, Macau)

 

Topics

(1) Formation, internal evolution, and dynamical evolution,

(2) Internal composition and structure,

(3) Atmospheric dynamics and circulation,

(4) Convection and heat transfer in deep interiors,

(5) Magnetohydrodynamics and magnetic field generation,

(6) Observational constraints from the Juno and Cassini missions,

(7) Observational constraints on the properties of Jupiter-like exoplanets,

(8) Comparison between Jupiter/Saturn and Jupiter-like exoplanets,

(9) Theory/computation of gravitational sounding, magnetic sounding, internal dynamics, and dynamics of the atmosphere,

(10) Ab Initio computation of the equation of state and internal structure.

 

Rationale

Jupiter and Saturn, the largest planets in our solar system, have always been prominent in scientific research
whilst Jupiter-like exoplanets have also become an important focus of intensive investigation.
The formation and interior structure of these planets are poorly understood yet central to our understanding of the architecture of our solar system and its similarities and differences to extra-solar systems. The Juno spacecraft, launched in August 2011, is now on its way to Jupiter and will arrive there in 2016. The Cassini spacecraft, already in orbit around Saturn, will perform a Juno-like survey of Saturn toward the end of its mission in 2016. These events will produce new data that promise exciting steps forward in our understanding of Jupiter and Saturn. Continued observation and data analysis of extra-solar Jupiters will also yield much new information about these bodies.

First, the physical and dynamical processes in the interiors of solar and extra-solar gas giants are fundamentally dependent on the equation of state (EOS) describing the relationship between pressure, density and temperature inside the planets. There are significant uncertainties in the EOS for the interiors of Jupiter, Saturn and Jupiter-like exoplanets
and these lead in turn to uncertainties about the composition and structure of their interiors and the process of formation and subsequent evolution. The high-precision measurements provided by the Juno and Cassini missions,
along with relevant theoretical and numerical modeling, will elucidate Jupiter and Saturn interior models, evolution and formation.
Second, a striking and fascinating feature of both Jupiter and Saturn is their fast, alternating, cloud level zonal winds, which provide valuable information about dynamical processes in their interiors. Despite the fact that the zonal winds have been accurately measured and extensively studied for a number of decades, their generation and maintenance still remain highly controversial. An objective of the Juno and Cassini spacecraft is to probe the extent of penetration of the zonal winds into the interiors of Jupiter and Saturn by accurately measuring their effects on the gravitational fields of the planets with unprecedentedly high precision. The measurements provided by the two missions, along with the relevant mathematical theories and accurate numerical modeling, will enable the resolution of this long-term scientific puzzle about Jupiter and Saturn.
Observations of extra-solar Jupiters together with dynamical modeling will throw light on whether these planets have wind systems similar to those of our own giant planets.
Third, Jupiter and Saturn share an essential dynamical feature: their deep interiors are thermally unstable and fluid motion driven by thermal instabilities and strongly constrained by rotation can effectively produce magnetic fields
via dynamo action in the highly electrically conducting material. Yet their fields are strikingly different in strength and geometry. Recent numerical models indicate that the form of the EOS and the internal structure of Jupiter and Saturn play a key role in the generation of their magnetic fields and that the stratification and magnetic field effects have substantial influence on the location and spatial structure of zonal winds. The high-precision measurements provided by the Juno and Cassini missions will also be able to provide useful constraints on the dynamos of Jupiter and Saturn. It would of course be illuminating to determine if extra-solar Jupiters also had magnetic fields, and that is an endeavor of current activity.
Fourth, the new observational constraints on Jupiter/Saturn and the corresponding new interior models they will generate will help us understand the important similarities and differences between Jupiter/Saturn and Jupiter-like exoplanets.


Since the Juno and Cassini missions will take place in 2016, 2017 would be timely for an International Astronomical Union (IAU) Symposium on the topics of atmospheres and interiors of Jupiter/Saturn and Jupiter-like exoplanets.
In this proposed IAU Symposium, the new observational constraints and discoveries from the Juno and Cassini missions
will be reported. New observational and theoretical developments of Jovian exoplanets will be presented. Physical interpretations for all these new measurements will be presented, and similarities and differences between the atmospheres and interiors of Juptier/Saturn and Jupiter-like exoplanets will be discussed.

We plan to hold the proposed IAU Symposium at the Space Research Institute of Macau University of Science and Technology
(MUST) for the following reasons. First, Macau has world first-class facilities for conferences and it is internationally easily accessible (about 50 minutes from the Hong Kong International Airport by ferry). Second, the Space Research Institute there has strong, active young staff who have played a leading role in planetary research in South East Asia and China. Third, the Space Research Institute is excited about holding the Symposium and is willing not only to act as the local organizer, but also to provide the required financial support, in addition to the IAU grant, for the Symposium.

We suggest that the Symposium be held from Wednesday 25th October 2017 -- Sunday 29th October 2017, a time of pleasant weather in Macau without climatic uncertainties.