Roe, Henry Lowell Observatory, Flagstaff, Arizona.
Lorenz, Ralph D. Space Department, Johns Hopkins University Applied Physics Laboratory, Laurel, Maryland.
Last reviewed:February 2019
Show previous versions
- History of observations
- Structure and composition
- Source of methane
- Seasons and time scales
- Clouds and circulation
- Huygens probe: Titan up close
- Related Primary Literature
- Additional Reading
The largest moon of Saturn and the only satellite in the solar system with a substantial atmosphere, as well as the only object, besides Earth, known to host stable bodies of liquid on its surface. Titan, 5150 km (3200 mi) in diameter, is the second largest natural satellite in the solar system, after Jupiter's Ganymede, and is larger than the planet Mercury. This large satellite's mass, 1.3452 x 1023 kg, is about two times that of the Moon, and has a lower mean density (1.9 g/cm3) than predominantly rocky, terrestrial worlds, indicating it contains a significant portion of icy and/or liquid material. Titan has an extended, dense atmosphere, mostly composed of nitrogen, that hides the surface in haze (Fig. 1). Given temperature and pressure conditions in this atmosphere, methane undergoes a meteorological cycle of evaporation and condensation, raining out of clouds, flowing as rivers, and pooling into lakes. The atmospheric chemistry and the solid surface on which liquids and aerosols can accumulate make Titan an attractive, natural, astrobiological laboratory for studying chemical evolution like that which ultimately led to life's emergence on the primitive Earth. See also: Astrobiology; Earth; Satellite (astronomy); Saturn; Solar system
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Contributors include more than 10,000 highly qualified scientists and 45 Nobel Prize winners.
MORE THAN 8700 articles covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 19,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information