Featured planetary moon
Iapetus
A two-toned moon with a ridge tracing its equator.
Iapetus presents one of the Solar System’s strongest hemispheric contrasts. A dark leading side, bright trailing terrain and a remarkable equatorial ridge give the distant moon a sharply asymmetric identity.
- Orbit representation
- Representative mean elements
- Surface
- procedural reconstruction
Reference measurements
The numbers that shape this world
- Mean radius
- 734.3 km
- Mean orbital distance
- 3,561,700 kmSemi-major axis around the parent body.
- Orbital period
- 79.331 days
- Eccentricity
- 0.028
- Inclination
- 7.6°Local Laplace plane from the JPL pole
- Rotation
- Tidally locked
World portrait
A world divided by light and terrain
The brightness contrast is reinforced by thermal feedback: darker areas absorb more sunlight and help maintain the separation between dark and bright terrain.
System geometry
Iapetus in motion around Saturn
Iapetus travels at a mean orbital distance of 3,561,700 km and completes a circuit in 79.331 days. Its eccentricity of 0.028 and 7.6° inclination are read against Local Laplace plane from the JPL pole. Synchronous rotation keeps the same hemisphere broadly oriented toward the parent body.
Representation notes
What Explore is showing
JPL fitted mean elements describe general orbit shape and orientation; they are not an accurate ephemeris.
Reference-guided visual reconstruction based on cited mission records; no source raster is reproduced.
Provenance