The storms arranged around a pole
Processed image. Roman Tkachenko processed JunoCam’s 2 February 2017 observation, captured at 06:06 PST about 102,100 kilometres above the clouds; published 8 February. Visible cloud texture complements the thermal-infrared products. Enhancement and different instrument footprints mean their colours and apparent storm boundaries are not interchangeable measurements.
Creative Commons Attribution (version not specified by source) · resized to WebP
· Original image source · Image licenceCompare visible cloud textures with infrared observations of an unexpected polar pattern.
- World
- Jupiter
- Case date or period
- Observations · 2016–2021
Look closer
A visible-light JunoCam view reveals the swirling southern atmosphere. JIRAM infrared observations let investigators compare the arrangement of cyclones over time, including a temporary additional storm. The instruments offer different views of the same polar region.
Follow the evidence
These are processed visible-light images, infrared products and annotated composites. Roman Tkachenko’s enhancement brings out cloud textures; JIRAM’s colours encode measured radiation rather than visible appearance. The dates, illumination and camera coverage matter when comparing individual storms.
Public image analysis helped reveal the polygon
John Rogers, Gerald Eichstädt and colleagues built polar projections from repeated JunoCam encounters. Their 2018 account explains that visible imaging could cover only sunlit parts of a pole, so a complete-looking southern map combined two flybys. JIRAM thermal-infrared observations supplied independent coverage across darkness. Comparing both instruments established the arrangement more securely than one photograph could. The assembled map represents multiple observation times, while the infrared colours express radiation rather than the storms’ visible colour.
Stable organisation still allows motion
Alessandro Mura and colleagues tracked cyclone centres in JIRAM observations spanning 2017–2020. The large southern arrangement persisted while its cyclones oscillated and the group drifted slowly; the temporary 2019 newcomer behaved differently from the long-lived storms. The study compares shallow and deep models, whose stability mechanisms make different demands on surrounding winds. Slow group motion favours a deep interpretation, but these measurements do not directly photograph the roots or fully explain why the cyclones avoid merging.
Sources & further reading
- Jupiter's South Pole Cyclones in 2016 — NASA Image and Video Library / JPL
- Jupiter's Pentagon Turns Hexagon — NASA Image and Video Library / JPL
- Jupiter's Polar Vortices Over Five Years — NASA Image and Video Library / JPL
- Jupiter’s polar polygons: Circumpolar clusters of cyclones — Rogers, Eichstädt and colleagues (2018) — BAA / independent processor and JunoCam researchers
- Oscillations and Stability of the Jupiter Polar Cyclones — Mura and colleagues (2021) — Geophysical Research Letters / JIRAM investigation
- The south pole in enhanced visible colour — NASA / JPL · public processor Roman Tkachenko