Titan

Moon· orbits Saturn

Titan is Saturn's largest moon and the only moon with a thick atmosphere — a hazy, organic-rich nitrogen world with rivers, lakes and seas of liquid methane and ethane on a frigid water-ice surface.

Open in 3D viewSee Titan in the live, interactive 3D map

Key facts

Mass

1.35 × 10²³ kg

0.0225 M⊕

Radius

2,575 km

1.48× wider than our Moon

Surface gravity

1.35 m/s²

14% of Earth's gravity

Day length

15.9 days

Orbit around Saturn

15.95 Earth days

Science

Physical

Mass: 1.35 × 10²³ kg · 0.0225 M⊕; JPL / IAU mean radii; spacecraft-tracked GM where measured
Radius: 2,575 km · 1.48× wider than our Moon; JPL SSD Planetary Satellite Physical Parameters (mean radius)
Density: 1,881 kg/m³ · 1.9× water; Computed from mass and radius
Surface gravity: 1.35 m/s² · 14% of Earth's gravity; Computed from mass and radius
Escape velocity: 2.64 km/s · 24% of Earth's escape velocity; Computed from mass and radius

Orbit around Saturn

Distance from Saturn: 1,221,900 km; From JPL orbital elements
Orbital period: 15.9 days; From JPL orbital elements
Eccentricity: 0.029; From JPL orbital elements
Inclination to Saturn's Laplace plane: 0.30 °; From JPL orbital elements · The Laplace plane is the one a moon's orbit precesses about: close in it is the planet's equatorial plane, the plane of the rings, and further out it tilts toward the planet's own orbit.

Rotation

Rotation period: 15.9 days
Tidal locking: Tidally locked to its parent

Atmosphere

Composition: ~95% N₂, ~5% CH₄
Surface pressure: 1.47 bar
Scale height: 40 km

Temperature

Surface: 94 K (-179 °C)

Composition

Bulk composition: A thick nitrogen atmosphere over a water-ice crust and a probable subsurface water–ammonia ocean, with a rock-rich interior; the surface hosts methane–ethane lakes.

Radiation & temperature

Insolation: 0.0112 S⊕ · 1% of the sunlight Earth receives; Computed from the distance to the Sun (inverse-square; Earth's sunlight = 1), before any atmosphere.
Bond albedo: 0.22 · reflects 22% of incoming sunlight
Equilibrium temperature: 85 K (-188 °C); Computed from albedo + distance from the Sun (airless black body)
Surface temperature: 94 K (-179 °C)
Greenhouse warming: +9 K; Measured temperature minus the airless equilibrium — the greenhouse effect

Discovery & history

Discovered: March 25, 1655
By: Christiaan Huygens
Method: Visual discovery (telescopic)
Name: The Titans of Greek myth; the name was proposed much later by John Herschel.

Christiaan Huygens discovered Saturn's largest moon in 1655. Titan is the only moon with a thick atmosphere and the only world besides Earth known to have standing liquid on its surface — but of methane and ethane, not water. In 2005 the Huygens probe parachuted to its surface, the most distant landing humans have ever achieved.