Namibian Sand Dunes Provide Insight Into Largest Moon of Saturn

The Dragonfly rotorcraft is scheduled to launch in 2028 and is expected to reach Titan, the largest moon of Saturn, in 2034. The rotorcraft will then spend 3.5 years exploring sand dunes and craters on Titan's surface, taking samples of surface materials and photographic imagery for analysis.

Titan is of particular interest to scientists due to its dense, nitrogen-rich atmosphere (like Earth) and the stable bodies of liquid (methane, ethane and dissolved nitrogen) on its frozen surface, perhaps providing insights into Earth's own origin and atmospheric chemistry. Racine Cleveland, who received her doctorate in space and planetary sciences from the University of Arkansas in the spring of 2026, hopes to be a part of the team analyzing those samples when the call for scientists comes.

Cleveland is in good position to do that as she was part of a NASA-funded expedition to Namibia in October 2025 to explore the dunes of the Namib Sand Sea, which are considered the closest earth analogue to what Dragonfly will encounter on Titan. The immense dunes are roughly the same size and shape as Titan's, and they interact with the underlying landforms in a similar way. Cleveland spent nine days in Namibia with 40 U.S. planetary aeolian (or wind) scientists and engineers getting a sense of the conditions on Titan.

"My Ph.D. was studying surface and atmosphere interactions on the South Pole of Mars and the equator of Titan," Cleveland explained. "I wanted to know what imagery could tell us about the atmospheres of these planetary bodies. I studied CO2 sublimation on the South Pole of Mars and how that adds or takes away from the mass balance of the CO2 total in the atmosphere. And then for Titan's dunes, I wanted to study how the shape of the dunes led us to an understanding of the wind patterns overall of the moon."

For Cleveland, the trip to Namibia was a chance to meet with the engineers who are building Dragonfly and get her foot in the door for later, when a team of scientists will be selected to analyze and interpret the data being collected on Titan. It was also a way to gain more context for understanding that data.

"Titan has a really dense atmosphere, so we can't see to the surface with visible imagery," Cleveland said. "We have to use radar to penetrate the clouds."

This means there is some guesswork to what they will find because radar can only provide the broad outlines of the dunes rather than their material composition.

"Dragonfly is going to land in a sand dune area," she explained. "The sand dunes are not what we might expect sand to be made of. They're potentially tarry, plasticky, not as rocky as we expect here. They're made of hydrocarbons whereas here, they're non-organics, silicates and things like that."

That said, wind likely sculpts the dunes in similar ways. Visiting the Namib Sand Sea gave them a sense of the dunes' slopes, the distances between them, the variations along the dunes' long axis as well as across them. Additionally, they got a sense of their roughness scale, which determines how much turbulence is created when wind passes over them.

Drones and small aircraft were flown to get a good overview of the interdune area. Anemometers were used to measure wind speeds, and neutron detectors were used to look at radiation differences among different surfaces: rubble, small grain sand and vegetated ground.

Cleveland noted that there are several kinds of sand dunes on Earth. Longitudinal dunes, which are the kind found in the Namib Sand Sea and that radar imagery indicates exist on Titan, are the longest dunes and created by a steady wind pattern over time. Star dunes are created by wind coming from multiple directions and have a clear peak and three or more radiating arms, like a starfish. Barchan dunes, found at the Great Sand Dunes National Park, form when there is a steady wind in one direction but limited sand, forming a horseshoe shape. She hopes to find multiple dune types on Titan.

Cleveland added that being part of the U of A's Center for Space and Planetary Science put her in a great position to join the future Dragonfly team.

"Our program is very diverse," she said. "Nobody works on the same project. And so being able to reach into each other's pockets of connections is what allowed me to be competent enough to do this. I spent five years studying Mars, knowing that I wanted to go on to Titan research. We have two other Titan researchers, but our research didn't overlap. But they had connections to people that I did overlap with, so I was able to get names and to have introductions made at conferences because of my fellow students that knew these people, knew their research, knew my research, and could make the connection for me."

Cleveland completed her Master of Science in geography at the University of Arkansas in 2023 and is now a postdoctoral fellow at Boise State University. She also received additional funding for the trip from the U of A Graduate School and International Education to cover the costs of food on her trip to Namibia.