FAQs: Frequently Asked Questions

7. Show me an example of how this works!

Here's an example of how the naming works for Saturn's largest moon, Titan. Titan has been observed extensively by the Cassini spacecraft, which has been orbiting Saturn since 2004. It has a thick atmosphere so we cannot see its surface, but the RADAR mapper on Cassini can see through the clouds. Below, you can see a RADAR map for a region near the north pole of Titan. We have learned that Titan has lakes, rivers and seas made of liquid methane and ethane. 


The Cassini scientists have been working with the International Astronomical Union to define the naming themes for Titan. Below is a table listing some of the themes. Each is associated with a particular type of feature.  You can see the complete list of feature types at the IAU's Planetary Nomenclature site.

When a scientist studying Titan needs to talk about a feature, it is time to give it a name. For example, if the feature is a small hill ("colla", plural "colles"), then according to the table, it needs a name associated with the characters from Middle-earth in the writings of J. R. R. Tolkien. This is how we now have a hill on Titan named Bilbo!

As another example, in the map above, the big sea is called "Kraken Mare" because, according to the table, seas ("maria") are named after sea creatures. The Kraken is a large sea monster resembling an octopus.

Feature Type Theme
Albedo features, terrae Sacred or enchanted places, paradise, or celestial realms from legends, myths, stories, and poems of cultures from around the world.
Colles Names of characters from Middle-earth, the fictional setting in fantasy novels by English author J.R.R. Tolkien (1892-1973).             
Craters and ringed features Gods and goddesses of wisdom.
Fluctūs Gods and goddesses of beauty.
Flumina Names of mythical or imaginary rivers.
Freta Names of characters from the Foundation series of science fiction novels by American author Isaac Asimov (1920-1992).
Insulae Names of islands from legends and myths.
Maria Sea creatures from myth and literature.
Montes Names of mountains and peaks from Middle-earth, the fictional setting in fantasy novels by English author J.R.R. Tolkien (1892-1973).
Planitiae and labyrinthi Names of planets from the Dune series of science fiction novels by American author Frank Herbert (1920 - 1986).
Sinūs Names of terrestrial bays, coves, fjords or other inlets.