Europa: measured position and radius, icy-surface imagery withheld

Measured facts

Classification

Galilean natural satellite

Parent body

Jupiter

Mean radius

1,561 kmPublished mean radius stored as renderer geometry.

Mean diameter

3,122 km

Mean radius in Earth radii

0.245

Appearance

Temporary educational representation

What you are looking at

Positions come from the measured archive rather than an assumed circular orbit, so the changing distance from Jupiter reflects the real eccentricity of the orbit.

A generalised planetary provider architecture handles the Jovian system: the same tile engine that serves Earth, the Moon, Mars and Mercury can accept a Galilean surface product when one is qualified.

Until then, Europa is a true-scale sphere with a marker and a documented absence of observational appearance.

Measured distance from Jupiter

These figures are magnitudes of the moon’s Jupiter-centred position vector, sampled once per day across 2020-01-01 00:00 TDB through 2040-01-01 00:00 TDB. They are distances from the centre of Jupiter, not from Earth, and they change because the orbit is not a perfect circle.

Distance from Jupiter at the snapshot epoch

672,252.1 km on 2026-08-29Magnitude of the Jupiter-centred position vector at the recorded ephemeris snapshot.

Closest measured approach to Jupiter

664,442.4 km on 2039-07-23

Farthest measured separation from Jupiter

677,707.6 km on 2039-06-16

Mean measured separation

671,088.9 kmSampled once per day across 2020-01-01 00:00 TDB to 2040-01-01 00:00 TDB (7,306 samples).

Archive cadence and held-out error

3.0 h sampling · 3.9 km worst held-out errorThe archive stores this moon relative to Jupiter so the large planet vector is not repeated per moon.

Delivery and camera limits

The camera stops at 1.08 mean radii for Europa. Educational geometry limit only; no observational surface imagery is integrated for this body yet.

Appearance status

Temporary educational representation

Renderer provider id

europa-visual-v1

Geometry

mean-radius-sphereMean-radius sphere; no ellipsoid or terrain displacement yet

Rotation model

IAU_EUROPA — pck00011 (2022-12-27)Source: https://naif.jpl.nasa.gov/pub/naif/generic_kernels/pck/pck00011.tpc

Limitations COSMOS discloses

• Appearance incomplete; no observational surface or atmosphere claimed
• No Galileo or Voyager surface mosaic is integrated.
• No subsurface-ocean, ice-thickness or terrain layer is claimed; none of those are rendered by COSMOS.
• Position is interpolated inside 2020-01-01 00:00 TDB through 2040-01-01 00:00 TDB; the ephemeris snapshot labelled 2026-08-29 00:00 TDB is the epoch used for the figures above.