Solar System Moons Series

Titan

The moon with atmosphere and rain: a world where methane plays the role of water.

Author: Juan Carlos Euyoque Aguilera · October 7, 2026 · CC BY 4.0

Image of Titan (NASA/JPL, public domain) — Titan (Cassini spacecraft, NASA/JPL, public domain). Not to scale.

5,150 km

Diameter

1,221,870 km

Distance from Saturn

94 K

Temperature

1.5 bar

Atmosphere

Titan orbits Saturn at 1,221,870 km and is the second-largest moon in the solar system, 5,150 km across. It is the only moon with a substantial atmosphere: 1.5 bars of nitrogen and methane — more surface pressure than Earth's.

At 94 K water is rock and methane rains: Cassini found lakes, seas and rivers of liquid methane and ethane — a complete hydrological cycle with different chemistry. NASA's Dragonfly mission will fly there in the coming decade.

Measured data [DATO]

Data	Value	Status	Source
Diameter	5,150 km	[DATO] observado	NASA Planetary Fact Sheets
Mass	1.3452×10²³ kg	[DATO] observado	NASA Planetary Fact Sheets
Mean density	1,880 kg/m³	[DATO] observado	NASA Planetary Fact Sheets
Surface gravity	1.352 m/s²	[DATO] observado	NASA Planetary Fact Sheets
Orbital period	15.945 days	[DATO] observado	NASA Planetary Fact Sheets
Rotation period	synchronous (15.945 days)	[DATO] observado	NASA Planetary Fact Sheets
Distance from Saturn	1,221,870 km	[DATO] observado	NASA Planetary Fact Sheets
Temperature	94 K (−179 °C, measured by Huygens)	[DATO] observado	NASA Science
Atmosphere	1.5 bar: nitrogen (95%) + methane	[DATO] observado	NASA Science
Notable feature	Liquid methane/ethane lakes and seas (Cassini radar)	[DATO] observado	NASA Science

Truths [DATO]

[DATO] Titan is the only moon with a thick atmosphere: 1.5 bars at the surface, with clouds, rain, and a methane cycle analogous to Earth's water cycle.
[DATO] Cassini mapped by radar hundreds of lakes and three large seas —Kraken, Ligeia and Punga— of liquid methane and ethane in the northern hemisphere.
[DATO] The Huygens probe landed on Titan in 2005 and photographed a dry riverbed with water-ice 'rocks': images taken from farther than any other surface.
[DATO] Beneath the ice crust there would be a global ocean of liquid water, separated from the outside by high-pressure ice.

Labeled myths [MITO]

[MITO] Titan's lakes are water.

False: they are liquid methane and ethane; at 94 K water is as hard as rock and forms the bedrock. Liquid water, if it exists, lies in a subsurface ocean.

Fuente: NASA Science

[MITO] There is life on Titan because it resembles the early Earth.

False: it is a prebiotic-chemistry laboratory, but no life has been detected; its chemistry runs on liquid methane, not water.