Workshop on Juno Prime Mission Results

June 20-24, 2022


Pasadena, California

Register by June 10 to facilitate planning.
Payment will be possible on-site.

Juno Workshop (Atmosphere, Interior and Origin)

Caltech, June 20-24, 2022

This workshop covers part of the wide-ranging science goals of the Juno mission; other aspects will be covered separately at later meetings. It is motivated by the Prime mission, but with the recognition that there are unanswered questions, some of which may be addressed in the extended mission, currently ongoing, but many will be outstanding and in need of more work, initiated or motivated by our meeting. This is a workshop, which means it is not a long sequence of presentations about current models and interpretations. It focuses instead on discussion groups devoted to outstanding questions. Participants are not merely presenters or spectators but are expected to contribute to that discussion through questions and suggested solutions or directions for future progress. As a consequence, remote participation is unlikely to work well and is discouraged.

There will be the opportunity to provide a poster and make a very brief advertisement for that poster, but the main structure will be three introductory overviews in plenary (in Sharp, a large lecture hall), followed by discussion groups in nearby classrooms, augmented by reassembly in plenary to present and discuss the outcome of the discussions.

Most of these discussions will be interdisciplinary. As examples: 

  • How do the predicted outcomes of planet formation compare with the interior models inferred from Juno gravity? 
  • How do we reconcile Juno gravity and MWR with the atmospheric composition inferred from the Galileo probe, accretion scenarios and other indications?
  • How do gravity, magnetic field, MWR, gravity, JIRAM and Junocam fit with our physical understanding of atmospheric flows (zonal winds, circulation and vortices and their respective depths, spatial and temporal structure)?

There will also be more focused discussions such as: 

  • Do we have the right equation of state? 
  • What does the magnetic field tell us about internal structure? 
  • Are the temperature and compositional anomalies suggested by MWR compatible with our current understanding of atmospheric dynamics, composition and heat flow?
  • What does Jupiter tell us about exoplanets?

Discussions may often be of order two hours in duration, but sometimes less. Importantly, the workshop is deliberately flexible, meaning that important issues or concerns can be responded to in real time by changing other topics or schedules.  

Refreshments and lunch will be available at cost and one evening dinner will be planned. We plan to begin on Monday morning (6/20), make Wednesday afternoon free,  and finish early Friday afternoon (6/24).

Suggestions for nearby hotels/motels (at a significant but walkable distance) will be provided. Visitor parking will be available at a modest cost. In this period, Caltech will be in summer session (no lecture classes) but will have a significant number of undergraduate researchers on campus (as usual) as well as the usual graduate population and researchers.

Warm sunny weather is likely but not guaranteed.

Juno Workshop Agenda

Download Schedule

Key Science Questions

Key questions on the atmosphere

Water and lightning
  • What are the various handles on the water abundance? What is the global value? How is water distributed with respect to latitude, altitude and time?
  • Moist convection - Differences from Earth; role in dynamics, temperatures, heat transport, clouds and chemical species
  • Lightning – Shallow vs deep? What are the various ways of detection? Optical power, occurrence frequency? What does it tell us about water, ammonia & deep convection?
  • What do we know?  Ammonia-rich air from 0-5N, ammonia-poor air from 3-15 bars at other latitudes, correlation of ammonia mixing ratio with belts and zones at 40-60 bars
  • Models – 3D GCMs with parameterized convection and precipitation. 2D (altitude-longitude) cloud-resolving models, 3D cloud-resolving models.
  • Relation to water – Mush balls and ammonia vapor bombs. How does internal heat get transported upward through the ammonia minimum at 3-15 bars?
Polar cyclones
  • What do we know? Winds, vorticity, anticyclonic shielding, upscale energy transfer
  • Comparison with vortex crystals in the laboratory. Effect of vanishing beta, shielding, PV staircase, radius of deformation. Can we observe forcing and dissipation of vortices?
  • Model reconciliation – shallow water, quasi-geostrophic, 1-layer, 2-layer, 2D, 3D; evolution from initial conditions vs continuous forcing/dissipation
Belts and zones
  • What do we know? Depth of NS asymmetry. Extension to latitudes beyond 25 degrees?  Is 3000 km decay with depth consistent with onset of electrical conductivity? Why not decay with distance parallel to rotation axis?
  • Eddy momentum flux in the clouds as a driver of vertical motion in belts and zones. Closure of meridional circulation – wave drag above the clouds, MHD drag below?
  • Where do the eddies get their energy – convection or baroclinic instability?

Key questions on the interior structure of Jupiter

  1. Composition and temperature profile of the deep atmosphere
    1. What is the composition and temperature profile of the deep atmosphere
    2. How do the uncertainties in temperature and composition affect our understanding of Jupiter’s interior structure?
    3. What are the requirements on amount of heavy elements in Jupiter’s envelope (Z)?
  2. How do the gravity, magnetic field and deep atmosphere couple?
    1. What is the internal structure that the gravity data requires/permits?
    2. What does the magnetic field tell us about Jupiter’s interior structure?
  3. What is the nature and origin of Jupiter's dynamic gravity?
    1. What can the tides tell us about Jupiter’s interior?
    2. What can normal modes tell us about Jupiter’s interior?
    3. Are there differentially rotating structures embedded in Jupiter’s deep atmosphere or interior?
  4. How do we reconcile accretion and evolution models with interior models?
    1. What are the constraints on the presence and mass of a diffuse core?
    2. What are the constraints on the presence and mass of an inner discrete core?
    3. Can Jupiter reduce the uncertainties in the equation of state?

Key questions in the origin of Jupiter

  1. Properties of Jupiter pertaining to its origin
    1. Abundance of water (oxygen) from Juno
    2. Distribution of the heavy elements (O,C,Ne,Fe,….)
      1. Oxygen at different depths (if available)
        1. What does sulfur tell us about the rock abundance?
        2. What do the trace species tell us about abundances and vertical mixing (AsH3, PH3, GeH4,….)
      2. Presence of alkali metals as a proxy for the rocky component
      3. Requirements from internal model and b.c. on envelope Z
    3. Presence and mass of a diffuse core
    4. Presence and mass of an inner discrete core
  2. Timing and number of stages in Jupiter formation
    1. Core formation (Stage I) plus gas+solid Stage II + gas Stage III?
      1. Stage I: Entropy, amount of mixing, role of pebbles in accelerating?
      2. Stage III: what determines Jupiter’s final mass?
    2. More intermediate stages? Timing?
    3. Process of heavy element addition to the envelope?
      1. Carriers: rock vs ice, what phase of ice.
      2. Timing: which Stage, post Stage III (late accretion)?
    4. Photoevaporation of the disk: When relative to Jupiter? How much?
  3. How does Jupiter fit in with the rest of the planets here and in exo-systems?
    1. Timing relative to terrestrial planets
    2. Timing relative to Saturn—Grand Tack
    3. Exo-Jupiters
      1. Range of heavy element abundances and correlation with mass?
      2. Accuracy of observations of C/O (range) in exo-Jupiters (hot or not)
      3. Other elements: S, N/O, Fe/O, PH3,
      4. JWST observations—can better observations of exoplanets better constrain g.p. formation
      5. Rings and dust disks in exoplanet systems—what do they tell us about planet formation?
      6. Gas accretion rates from direct imaging of disks?
  4. What do the Galilean moons have to tell us about Jupiter’s formation?
    1. (Limited to general discussion as satellites not in workshop)

Important Dates

Registration Opens May 16, 2022
Attendance Registration Deadline Jun 10, 2022
RSVP for Dinner Party Jun 10, 2022
Dinner Party Jun 22, 2022


$35 (covers incidental charges)

  • Payable at the workshop.
  • Waived for students.
  • Optional lunches can be added at the time of registration.
Register Now


Some possibilities near Caltech are:

Pasadena Rose & Crown Hotels

1203 E. Colorado Blvd, Pasadena, CA, 91106
(626) 449-3170

0.7 miles away, directly north of Caltech

Howard Johnson by Wyndham Pasadena

1599 E Colorado Blvd, Pasadena, CA 91106
(626) 808-4500

0.8 miles away, adjacent to Pasadena City College

Saga Motor Hotel Pasadena

1633 E Colorado Blvd, Pasadena, CA 91106
(626) 795-0431

0.9 miles and on Colorado, a popular choice and longer walk

Travelodge by Wyndham Pasadena Central

2131 E Colorado Blvd, Pasadena, CA 91107
(626) 796-3121

2-star hotel
1.3 miles, substantially longer walk

Hilton Pasadena

168 S Los Robles Ave, Pasadena, CA 91101
(626) 577-1000

3-star hotel

Sheraton Pasadena Hotel

303 Cordova St, Pasadena, CA 91101
(626) 469-8100

3-star hotel
(longer walk, often used for DPS)

The Westin Pasadena

191 N Los Robles Ave, Pasadena, CA 91101
(626) 792-2727

4-star hotel

Further away, requires transportation to get to Caltech. Parking at Caltech is possible for a modest cost.

Courtyard by Marriott Los Angeles Pasadena/Old Town

180 N Fair Oaks Ave, Pasadena, CA 91103
(626) 403-7600

3-star hotel

Residence Inn by Marriott Los Angeles Pasadena/Old Town

21 W Walnut St, Pasadena, CA 91103
(626) 204-9220

3-star hotel


The workshop is scheduled to be held in Pasadena, CA at Caltech June 20-24, 2022. There will be 3 introductory overviews in Sharp Lecture Hall, followed by discussion groups in nearby classrooms.