Space Time logo Space Time
Moon · evidence and sources

Iapetus

Two-toned outer moon of Saturn famous for its dark leading hemisphere and equatorial ridge.

Kepler elements Orbit basis, the same label the app shows on the selection card.

Open in Space Time

Every aspect, with its origin

One record per aspect. The origin says what kind of thing each value is; the source says where it came from; the limit says what it cannot tell you.

ObservedCatalogComputedReconstructedIllustrativeUndocumented
Orbit Computed

Orbit from mean elements

Iapetus is placed by solving a Keplerian orbit around saturn at the simulation time (a = 3,560,854 km, e = 0.0286, i = 15.5°, period 79.3 d).

SourceBundled orbital elements
MethodTwo-body propagation of the stored elements by the shared orbit service; no perturbations.
LimitA two-body orbit ignores perturbations, and the object catalog does not record which element table these values were copied from.
Physical data Undocumented

Bulk properties

Iapetus: mean radius 734.5 km. These values are bundled with the object record and drive the rendered size.

SourceBundled object record
LimitThe object catalog does not record where these values came from; treat them as unverified until the record is completed.
Appearance Reconstructed

Cassini spacecraft mosaic

Grayscale spacecraft mosaic with variable resolution and baked-in photographic shadows. Not calibrated color or measured terrain relief.

SourceAppearance source and method
MethodThis describes the displayed appearance only; it does not certify catalog dimensions, orbital elements or unobserved geology.
Appearance Reconstructed

Iapetus: the map behind the view

Grayscale spacecraft mosaic with variable resolution and baked-in photographic shadows. Not calibrated color or measured terrain relief.

SourceCassini / NASA, JPL-Caltech, Space Science Institute; USGS mapping
MethodSource maps are compared with a physical globe or rings under simulated illumination. The image and camera view are not registered.
LimitGrayscale spacecraft mosaic with variable resolution and baked-in photographic shadows. Not calibrated color or measured terrain relief.
Description Undocumented

Description and facts

The short description and the fact list are written by the Space Time authors for orientation. They are not quoted from a catalog field and carry no citation of their own.

SourceSpace Time editorial text
LimitBackground reading is linked under Further reading; it is not the source of the displayed numbers.

What is not measured

  • Appearance: a reconstruction from measurements, not a direct observation. Cassini spacecraft mosaic. Grayscale spacecraft mosaic with variable resolution and baked-in photographic shadows. Not calibrated color or measured terrain relief.
  • Appearance: a reconstruction from measurements, not a direct observation. Iapetus: the map behind the view. Grayscale spacecraft mosaic with variable resolution and baked-in photographic shadows. Not calibrated color or measured terrain relief.

Not yet documented

  • Physical data: The object catalog does not record where these values came from; treat them as unverified until the record is completed.
  • Description: Background reading is linked under Further reading; it is not the source of the displayed numbers.

Dataset freshness

Snapshots this page depends on, read from the generated manifests at request time.
DatasetLast refreshedHorizonAutomated
Planetary satellite mean elements
JPL Solar System Dynamics
 no snapshot date Mean elements (a, e, i, period) for every known natural satellite No, refreshed by hand
npm run generate:moons

Sources cited

Further reading

Wikipedia: Iapetus (background only; not the source of the displayed numbers)

More

All evidence pages Sky events and alert sources What's new All features
Space Time is a free 3D universe explorer by Point Dynamics. Origins: how to read these pages.