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July 31, 2026Short & citedBlog
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Field Notes • Astronomy

Titan (moon)

Titan is Saturn’s largest moon and the second-largest moon in the Solar System.

Updated July 31, 20261 min readCited sources

Titan is Saturn’s largest moon and the second-largest moon in the Solar System. It is the only moon known to have a dense atmosphere and stable liquids on its surface.

Discovery and naming

Titan was discovered in 1655 by Dutch astronomer Christiaan Huygens. It was the first planetary satellite found after the Galilean moons of Jupiter, and it remains one of the most intriguing moons for study.

Physical characteristics

Titan is the second-largest moon in the Solar System, larger than Mercury in diameter. Its icy surface and very low temperature (about -179 °C) allow methane and ethane to exist as liquids, forming lakes, seas, and rivers.

Atmosphere and weather

Titan has a thick, nitrogen-rich atmosphere with methane and haze—the only moon with a substantial atmosphere. It experiences weather cycles of rain, rivers, lakes, and seas, similar to Earth but with methane and ethane.

In short

  • Titan is Saturn’s largest moon and second-largest in the Solar System.
  • It is the only moon with a dense, nitrogen-rich atmosphere.
  • Titan is the only place besides Earth with stable surface liquids.
  • Discovered by Christiaan Huygens in 1655.
Canadian angle

Titan is a major target in planetary science followed by Canadian researchers and institutions through international missions such as Cassini-Huygens, with Canadian readers often encountering Titan in astronomy education and space-science coverage.

Quick questions

What is Titan?
Titan is Saturn’s largest moon and the second-largest moon in the Solar System.
Does Titan have an atmosphere?
Yes. Titan is the only moon known to have a substantial, dense atmosphere.
Does Titan have liquid on its surface?
Yes. It is the only place besides Earth known to have stable liquids on its surface.

Sources

  1. NASA Sciencehttps://science.nasa.gov/saturn/moons/titan/facts/
    Supports: Titan is Saturn’s largest moon, the only moon with a substantial atmosphere, and the only place besides Earth known to have liquids on its surface.
  2. European Space Agencyhttps://www.esa.int/Science_Exploration/Space_Science/Cassini-Huygens/Facts_about_Titan
    Supports: Titan is Saturn’s largest moon, the second largest in the Solar System, discovered by Christiaan Huygens in 1655.
  3. Encyclopaedia Britannicahttps://www.britannica.com/place/Titan-astronomy
    Supports: Titan’s discovery, dense atmosphere, and status as the only body other than Earth known to currently have liquid on its surface.
  4. NASA Sciencehttps://science.nasa.gov/mission/cassini/science/titan/
    Supports: Titan has lakes and seas of liquid methane and ethane, hydrocarbon dunes, and evidence for a large internal ocean.