NASA's Completed Geologic Map of Saturn's Moon Titan Offers Glimpse of its Exotic Terrain
NASA scientists revealed the first-ever global geological map of Saturn's moon Titan yesterday, giving a glimpse of the icy giant's (it's our solar system's second largest moon, bested only by Jupiter's moon Ganymede) topological features that lie in its methane-rich atmosphere.
The map was created from data gleaned by the Cassini space probe, which ended its two-year mission in late 2017, and presents an interesting portrait of Titan's lakes – made up of liquid methane and other organic compounds – and its equatorial dunes and hummocks (small hills) punctuated by a few craters. A 3-D navigable version of the map, using images from NASA, is already available on Google Maps. The map suggests phenomena similar to those that take place on Earth in its shaping its terrain.
"Despite the different materials, temperatures and gravity fields between Earth and Titan," said NASA/JPL planetary geologist and lead researcher Rosaly Lopes, "many surface features are similar between the two worlds and can be interpreted as being products of the same geologic processes. The map shows that the different geologic terrains have a clear distribution with latitude, globally, and that some terrains cover far more area than others."
Although water vapor has been confirmed on Jupiter's moon Europa and liquid water is theorized to exist beneath its icy surface, Titan is the only body in our solar system other than Earth known to have liquid on its surface. That liquid, of course, isn't water, but rather ethane and methane, which rain down as liquids in the planet's sub-zero temperatures. "The Cassini mission revealed that Titan is a geologically active world," said David Williams, a planetary geologist from School of Earth and Space Exploration at Arizona State University who worked with Lopes on the project, "where hydrocarbons like methane and ethane take the role that water has on Earth. These hydrocarbons rain down on the surface, flow in streams and rivers, accumulate in lakes and seas, and evaporate into the atmosphere. It's quite an astounding world!"
The presence of organic compounds has led some news outlets to speculate about the possibility of lifeforms on Titan, a possibility not ruled out by the researchers. "Organics are very important for the possibility of life on Titan, which many of us think likely would have evolved in the liquid water ocean under Titan's icy crust," Lopes said. "Organic materials can, we think, penetrate down to the liquid water ocean and this can provide nutrients necessary for life if it evolved there."
The research was published in the journal Nature Astronomy.