Saturn: a dated Hubble cloud-top map over measured rings

Measured facts

Classification

Gas giant planet

Mean radius

58,232 kmPublished mean radius stored as renderer geometry.

Mean diameter

116,464 km

Reference shape

Oblate reference ellipsoid · flattening 0.0980Equatorial 60,268 km, polar 54,364 km. No terrain displacement or cloud-height model.

Mean radius in Earth radii

9.14

Appearance

Atmospheric observation · cloud tops

Observation epoch

2025-08-29 Rotation A (05:53:28–14:20:17 UT)

What you are looking at

The OPAL Cycle 32 Rotation A colour composite was acquired on 2025-08-29 and spans 05:53:28 to 14:20:17 UT. It uses F631N, F502N and F395N filters with slight contrast enhancement, and it is a global map of cloud tops at about 210 km equatorial sampling.

The rings are not a texture. NASA ring boundary radii were converted to metres and drawn as six thin body-equatorial annuli: D, C, B, the Cassini Division as a physical gap, A and F.

The globe uses a reference oblate ellipsoid based on the OPAL limb-fit radii, and its orientation comes from IAU_SATURN at the selected TDB epoch.

Approach is capped at 4 equatorial radii so the 1,800-pixel global map remains a meaningful screen-scale cloud-top view.

Distance, scale and light time

Distances here are computed from the shipped JPL Horizons state archive, sampled once per day across its declared coverage (2020-01-01 00:00 TDB through 2040-01-01 00:00 TDB). Because both bodies move on different orbits, the separation changes constantly; the figures below include the dates at which the extremes occur.

Distance from Earth

8.631 AU · 1,291,110,351 kmAt the recorded snapshot epoch 2026-08-29 00:00 TDB, one-way light time 71.78 minutes.

Distance from the Sun

9.445 AU · 1,412,909,454 kmComputed in the same epochs and frame (Earth-centred ecliptic J2000.0 / ICRF).

Closest Earth approach in the archive

8.031605 AU on 2032-12-25One-way light time then: 66.8 minutes.

Farthest separation in the archive

11.016491 AU on 2020-01-13One-way light time then: 91.62 minutes.

Mean separation across the archive

9.430369 AUSampled once per day across 2020-01-01 00:00 TDB through 2040-01-01 00:00 TDB (7,306 samples).

Delivery and camera limits

COSMOS stops the camera at 4.0 equatorial radii for Saturn. Atmospheric maps are protected because their delivered sampling is coarse relative to the disk, and an unlimited zoom would present interpolated pixels as atmospheric detail.

Appearance status

Atmospheric observation · cloud tops

Renderer provider id

saturn-visual-v1

Declared resolution

5 pixels per degree; approximately 210 km equatorial map sampling, not a uniform atmospheric feature-resolution claim

Closest permitted approach

4.0 equatorial radiiReference oblate equatorial radius 60,268 km; the floor protects the delivered cloud-top map from being enlarged beyond a meaningful atmospheric view.

Rotation model

IAU_SATURN — pck00011 (2022-12-27), IAU 2015 Saturn modelSource: https://naif.jpl.nasa.gov/pub/naif/generic_kernels/pck/pck00011.tpc

Geometry

oblate-reference-ellipsoidReference oblate ellipsoid; no terrain displacement and no cloud-height model

Provenance

Appearance provenance is carried by the provider at runtime, not added by the page: an active appearance layer is registered.

Category

observational-composite

Provider

MAST/STScI · Hubble Outer Planet Atmospheres Legacy

Project / mission

Hubble Space Telescope WFC3/UVIS · OPAL Cycle 32

Dataset

hlsp_opal_hst_wfc3-uvis_saturn-2025a_f395n-f502n-f631n_v1_globalmap

Version

Cycle 32 Rotation A; source bytes checked 2026-09-06

Licence

MAST HST data policy; retain NASA, ESA, STScI, and OPAL credit

Attribution

NASA, ESA, STScI, and the OPAL team

Source checked

2026-09-06

Limitations COSMOS discloses

• Cloud-top observation only; no solid visible surface is implied
• Historical hlsp_opal_hst_wfc3-uvis_saturn-2025a_f395n-f502n-f631n_v1_globalmap does not update with selected ephemeris date
• Detail stops at the declared approximately 210 km atmospheric-map ceiling
• A dark near-equatorial stripe and dark polar patches are present in the delivered source image. They are retained and disclosed rather than filled, and COSMOS does not claim they are validated ring shadows.
• Moon and shadow crossings visible in the source observation remain part of the historical image.
• The rings are annular geometry at published radii: not particle-scale ring imagery and not a simulated density field.
• No solid landing surface or terrain displacement is claimed.
• Position is interpolated inside 2020-01-01 00:00 TDB through 2040-01-01 00:00 TDB; requesting an epoch outside that window is rejected instead of extrapolated.