← World catalog MOON / 06
Ganymede
Jupiter
The Solar System's largest moon, with an intrinsic magnetic field and evidence for a deep, layered saltwater ocean.
BEvidence classStrong inference from multiple independent measurements
- Mean radius
- 2,634.1 km
- Surface gravity
- 1.428 m/s²
- Representative temperature
- about −163 °C surface
- Surface pressure
- Extremely tenuous O₂ atmosphere
Scientific assessment
Magnetic and auroral observations support liquid layers, although high-pressure ice may separate the ocean from rock.
- Liquid-water evidence
- Deep subsurface ocean, strong geophysical inference
- Principal constraint
- Deep ocean and possible high-pressure ice barrier
- Principal mission context
- ESA JUICE; Galileo and Hubble archives
Comparative evidence matrix
A transparent research-priority index, not a probability of life. It combines solvent evidence, usable energy, chemistry, environmental stability, evidence maturity, and sampling access.