← scientific atlas

archive / atlas record

Ganymede

The largest moon and the only one known with an intrinsic magnetic field.

classification
Icy moon
system
Jupiter system
overview //

Ganymede is larger than Mercury and contains a differentiated interior, an icy shell and evidence for a buried ocean.

technical data //
Class
Icy moon
Location / system
Jupiter system
Distance
1.07 million km mean distance from Jupiter

Only values with an established scientific consensus are listed. Where a quantity is uncertain or model-dependent, it is discussed in the sections below rather than stated as data.

what we know //
01

Overview (starter entry, expanded review pending)

Ganymede is larger than Mercury and contains a differentiated interior, an icy shell and evidence for a buried ocean.

how do we know? //

Imaging, spectra and orbital dynamics

Ganymede's surface or atmosphere is constrained by telescopic and spacecraft imaging where available; spectra identify materials, while repeated position measurements establish its orbit and system context.

methods archive →
open questions //
  • What remains least constrained about Ganymede?Composition, internal structure, formation history or local environment can require different observations and may remain model-dependent.

Items above are unresolved. Hypotheses are labelled as such and are not presented as confirmed findings.

related missions //
JUICE studies the Jupiter system; its observing programme and targets differ by moon.
mission tracker →
sources / data //editorial standard →
  1. NASA // verified 28 September 2026

    Planetary Fact Sheet ↗

  2. NASA/JPL // verified 28 September 2026

    Horizons System ↗

continue exploring //