It is a big week of space news. Not only has a leading professor put forth evidence for life on Mars but NASA has just finished mapping the surface of Titan and it looks more like Earth than any planet or moon in our solar system. It has craters, dunes, lakes, rolling hills and rivers. They are just not made of the same things we expect on Earth.
What is Titan?
Titan is Saturn’s largest moon and is the second largest moon in our solar system. It is between our moon and Earth in size.
Titan is the only other body in the solar system with liquid on its surface and a geology that seems similar to earth. However, it is also very alien. The lakes and rivers are made of liquid methane and ethane. It has seas that are hundreds of miles wide and hundreds of feet deep. All of this is on top of a thick crust of water ice, which is above a subsurface ocean of liquid water. It also has an atmosphere rich in hydrocarbons, very similar to Earth.
Titan’s subsurface water could be a place to harbor life as we know it, while its surface lakes and seas of liquid hydrocarbons could conceivably harbor life that uses different chemistry than we’re used to—that is, life as we don’t yet know it.NASA
How did NASA map Titan?
The Cassini missions which flew by Titan between 2004 and 2017 yielded data for about 120 flybys of the exotic moon. Scientists from NASA’s Jet Propulsion Laboratory then combined all of this data to generate a comprehensive map of the surface.
The atmosphere of Titan is very thick so they relied heavily Cassini’s radar to penetrate the atmosphere and show details of the surface. While it has been known for some time that it is both similar and very alien to Earth, the new data confirms many interesting details.
Roughly two thirds of the moon is covered in flat plains. Near the equator, there are sand dunes, which cover about 17% of the surface. 14% consists of hilly terrain with lakes of methane and ethane and rivers. Rivers carved deeply into the surface in other places, creating large valleys.
NASA is now planning its Dragonfly mission which will test the moon’s surface for life in 2034.