Moons · Space Codex
Enceladus
The most reflective world in the Solar System.
The moon that sprays its ocean into space
At a glance
Key points
Jets from cracks at its south pole vent an underground ocean into space, building one of Saturn's rings.
- Reflects essentially all the sunlight that hits it
- 101 geysers vent its ocean into space
- Its plumes build Saturn's E ring
Plumes
Cassini found the plumes in 2005. Ice grains and gas leave the south-polar fractures at around 400 m/s; some fall back as snow, the rest feed Saturn's broad E ring. Cassini flew through the spray several times and tasted water, carbon dioxide, methane, ammonia, salts and tiny grains of silica.
A habitable ocean?
Silica nanograins form when hot water, above about 90 °C, reacts with rock, which points to hydrothermal vents on the seafloor. In 2023 researchers reported phosphate in plume grains at concentrations at least 100 times those of Earth's seawater; in 2025 a reanalysis found new complex organic molecules in freshly ejected grains.
Surface
The north is cratered and old, the south nearly crater-free. Four parallel fractures, each about 130 km long, cross the south pole; in true colour they are only faintly bluish-grey.
What we still don't know
Whether life could exist in an ocean this small, and how long the ocean has been liquid.
Missions
- 1977–
The only spacecraft to visit Uranus (1986) and Neptune (1989); interstellar since 5 Nov 2018.
- 1997–2017
Cassini–Huygens
NASA / ESA / ASICompletedOrbited Saturn 2004–2017 and ended by diving into the planet.
First-hand · our 3D model
How we render it
Enceladus is a sphere wrapped in a global map built from USGS and NASA spacecraft mosaics. At full quality a plume rises from the south-polar fractures, drawn as an additive cone that only really shows when Enceladus is backlit, as in Cassini's images.
It is drawn at about 2.7% of Saturn's radius, enlarged from its true 0.43% so it stays visible. It orbits almost exactly in Saturn's equatorial plane, with a 1.37-day period kept in true ratio to its neighbours, and keeps one face towards Saturn.
Moon sizes and orbits are compressed so a whole system fits on screen, but never reordered: each moon is drawn at 0.72 × (true size ratio)^0.6 of its planet, capped so no large moon is drawn bigger than it really is, and orbit distances are log-compressed into a band that clears the planet's rings. Orbital periods keep their true ratios, every moon is tidally locked, and on lighter devices only the two largest moons of each planet are drawn.
Related entries
Sources
- Postberg et al. 2023, Nature 618:489 (FU Berlin summary) (opens in a new tab)
- NASA NSSDC Saturnian Satellite Fact Sheet (opens in a new tab)
- JPL Solar System Dynamics: satellite physical parameters (opens in a new tab)
- JPL Solar System Dynamics: satellite mean orbital elements (opens in a new tab)
- NASA Science: Enceladus (opens in a new tab)
- NASA JPL: Cassini reveals 101 geysers (opens in a new tab)
Last reviewed against these sources. Built from public NASA, ESA and JPL data; not affiliated with or endorsed by any agency.