← World catalog MOON / 02
Europa
Jupiter
An ice-covered moon with strong evidence for a global salty ocean and ongoing tidal energy.
BEvidence classStrong inference from multiple independent measurements
- Mean radius
- 1,560.8 km
- Surface gravity
- 1.315 m/s²
- Representative temperature
- about −160 °C surface
- Surface pressure
- Extremely tenuous O₂ atmosphere
Scientific assessment
Magnetic induction, surface geology, and gravity constraints jointly support a subsurface ocean beneath an ice shell.
- Liquid-water evidence
- Global subsurface ocean, strong geophysical inference
- Principal constraint
- Radiation and uncertain ice thickness
- Principal mission context
- NASA Europa Clipper; ESA JUICE context
Separated context matrix
Six editorial comparison inputs are shown separately. They are not combined into a probability of habitability or life. Conditional research priorities are calculated only in the scenario laboratory with visible assumptions, uncertainty and hard eligibility gates.
Europa / System profile
Measured and inferred parameters are labeled by evidence class.
A
Directly observed or repeatedly measured
B
Strong inference from multiple independent measurements
C
Model-dependent or indirect interpretation
D
Unknown or not yet constrained
Interior architecture
A layered physical model from observable surface to uncertain deep interior.
01A
Radiolysed surface
Jovian radiation creates oxidants and rapidly alters exposed material.
02C
Ice shell
Thickness and degree of convection remain major unknowns; fractures may exchange material.
03B
Salty ocean
Magnetic induction strongly supports a conductive global liquid layer.
04C
Rocky seafloor
Potential water–rock reactions and hydrothermal energy are plausible but unsampled.
Matter and energy pathways
Processes that connect solvent, chemistry, energy and environmental persistence.
1
B Tidal flexing → heat
Orbital resonance dissipates energy inside the ice and interior.
2
C Surface oxidants → ocean
Transport through disrupted ice could supply chemical gradients.
3
C Ocean ↔ rock
Direct contact would enable mineral reactions important to habitability.
Evidence ledger
Claims remain separate from the observations or models that support them.
Global conductive layer
BasisGalileo magnetic induction measurements.
Young mobile ice surface
BasisFew craters, ridges, bands and disrupted terrain.
Active plumes
BasisCandidate remote detections are intermittent and not yet definitive.
Present biology
BasisNo direct sample from the ocean.
Observation chronology
The measurements and missions that changed the scientific interpretation.
Voyager images reveal a fractured young surface.
Galileo constrains geology, gravity and induced magnetism.
Europa Clipper launched for detailed reconnaissance.
Planned arrival of Europa Clipper at Jupiter.
Knowledge frontier
Unresolved questions and the observation needed to reduce uncertainty.
Q01C
How thick and permeable is the ice?
Resolution pathIce-penetrating radar, topography and gravity flybys.
Q02D
What is the ocean’s chemistry?
Resolution pathSurface spectroscopy and analysis of any lofted material.
Q03C
Does ocean water contact rock?
Resolution pathCombined magnetic, gravity and thermal interior models.
Competing explanations
The evidence is read against alternatives. A habitable environment, a detectable signal and a biological explanation are separate claims.
Test this world in the scenario simulator →Scientific state vector
Uncertainty and decision laboratory
A reproducible Rust ensemble propagates uncertainty through the declared decision scenario. Results are conditional research priorities, never probabilities of life.
Ready to calculate
Local sensitivity
Knowledge gaps and mission design
The engine ranks uncertainty that can change a decision, then compares mission architectures under explicit resource constraints.
Priority knowledge gaps
Calculating…
Mission architecture sandbox
Calculating…
Comparative research model — not a flight design or cost estimate.