NASA Creates First Topographical Map of Titan, Saturn's Largest Moon

For the first time, scientists have created a topographical map of Saturn’s largest moon Titan, giving researchers a crucial tool in learning more about one of the most Earth-like bodies in the solar system.

“Titan has so much interesting activity – like flowing liquids and moving sand dunes – but to understand these process it’s useful to know how the terrain slopes,” Ralph Lorenz, a member of the Cassini radar team based at the Johns Hopkins University Applied Physics Laboratory and the lead researcher on the map-design team, said in a press release. “It’s especially helpful to those studying hydrology and model Titan’s climate and weather, who need to know whether there is high ground or low ground driving their model.”

With a radius of nearly 1,600 miles, the moon is bigger than Mercury and is the second largest moon in the solar system. Furthermore, it’s the only moon in the solar system to boast clouds, surface liquids and a mysterious, thick atmosphere composed of nitrogen like Earth’s. However, the organic compound methane on Titan acts the way water vapor does on Earth, even forming clouds and falling as rain and carving the surface with rivers.

Organic chemicals derived from methane are present in Titan’s atmosphere as well as lakes and rivers and, scientists hope, may offer some clues into the origins of life.

This hazy environment, however, scatters light in a way that makes it nearly impossible for remote cameras to catch a glimpse of the landscape shapes and shadows, hence the reason researchers only now have finished the topographic map – a project achieved through the space craft Cassini’s radar imager during its nearly 100 flybys over the planet.

“With this new topographic map, one of the most fascinating and dynamic worlds in our solar system now pops out in 3D,” Steve Wall, the deputy team lead of Cassini’s radar team, said. “On Earth, rivers, volcanoes and even weather are closely related to heights of surface – we’re so eager to see what we can learn from them on Titan.”

There are still challenges, however, given the fact that the team has only imaged about half of Titan’s surface.

To fill in the gaps, Lorenz’s team used a mathematical process calling splining in which they used models to fill in the holes with what is most likely there.

Thus far, estimations fit with current knowledge of the moon, including that its polar regions are “lower” than areas around the equator, though Lorenz said it would probably be worth revising when Cassini’s mission ends in 2017.

Regarding his decision to go ahead despite the lack of information Larenz said, “We felt we couldn’t wait and should release an interim product,” adding that the “community has been hoping to get this for a while.”

In the end, complete or not, Larenz said he believes it will “stimulate a lot of interesting work.”