Moons · Space Codex
Titan
Larger than Mercury and wrapped in a nitrogen atmosphere thicker than Earth's.
A moon with weather, rivers and seas
At a glance
Key points
Methane falls as rain, carves rivers and fills seas at −180 °C, the only stable surface liquid known beyond Earth.
- Only moon with a thick atmosphere
- Rain, rivers and seas made of methane and ethane
- Dragonfly launches no earlier than July 2028
Atmosphere and weather
Sunlight breaks apart methane high in the atmosphere, and the fragments rebuild into an orange smog of organic molecules that hides the surface in visible light. A separate, thin blue haze layer floats above it. Methane clouds form, rain falls, and the liquid runs off into channels, lakes and seas, a full hydrological cycle with methane playing the part of water.
Surface
Radar and infrared cameras on Cassini mapped dark equatorial dune fields of organic sand, the bright highland region Xanadu, and seas of liquid methane and ethane clustered near the north pole. Kraken Mare is about five times the size of Lake Superior. On 14 January 2005 the Huygens probe parachuted down and landed on a damp plain strewn with rounded ice pebbles.
Interior
Cassini measured how much Titan flexes in Saturn's gravity, and the answer requires a global ocean of salty water, perhaps mixed with ammonia, beneath an ice shell tens of kilometres thick.
Exploration
NASA's Dragonfly, a nuclear-powered rotorcraft, is due to launch no earlier than July 2028 and reach Titan around 2034. It will fly between dune sites and Selk Crater, where melted ice once mixed with surface organics.
What we still don't know
How far prebiotic chemistry has progressed on Titan, and whether the deep ocean ever exchanges material with the organic-rich surface.
Missions
- 1977–
Jupiter 1979, Saturn 1980; interstellar space since 25 Aug 2012.
- 1997–2017
Cassini–Huygens
NASA / ESA / ASICompletedOrbited Saturn 2004–2017 and ended by diving into the planet.
- 14 Jan 2005
Huygens probe
ESACompletedLanded on Titan: the most distant landing ever made.
- Launch NET Jul 2028
Nuclear-powered rotorcraft; arrives at Titan around 2034 for a 3.3-year mission.
First-hand · our 3D model
How we render it
Titan has no visible surface in the model, just as in visible light: it is an opaque, butterscotch haze ball with latitude toning, a soft limb that fades with the ray's path through the haze rather than a hard edge, and a thin detached blue-violet haze layer at about 1.19 Titan radii. Both layers brighten when Titan is backlit.
It is drawn at about 11% of Saturn's radius, enlarged from its true 4.4% so it stays visible. It orbits in Saturn's equatorial frame, inclined 0.3°, with a 15.95-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
- 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 NSSDC Saturnian Satellite Fact Sheet (opens in a new tab)
- ESA: Fulchignoni et al. 2005 (Huygens HASI) (opens in a new tab)
- NASA Science: Titan (opens in a new tab)
- NASA JPL: Cassini radar sounds Ligeia Mare (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.