A new study recently published in Nature revealed more details about the mysterious mechanism that led to the creation of the massive and unusually looking dunes on Titan, Saturn’s largest moon. Scientists say that Titan, Mars and Venus are the only bodies in our solar system to have such dunes on their surface.
Titan is also the only celestial body in our solar system other than Earth to hold liquid on its surface. Scientists say that the Cassini orbiter shows this strange moon has dozens of lakes filled with methane and ethane. In lower altitudes the probe has also discovered unusually high sand dunes.
Astronomers say that although Mars and Venus host similar dunes, the dunes on Titan are very different both in their sand and the winds that shaped them.
“The dunes are not made of silicates – sand – as on Earth or Mars. They’re hydrocarbons, and may possibly include particles of water ice that are coated with these organic materials,”
Devon Burr, a former SETI planetary scientist and lead author of the study published in Nature, said.
Researchers say that they couldn’t find out the source of these hydro carbonaceous particles, but they were able to learn more about the winds that permanently give shape to Titan’s dunes.
Researchers analyzed the shape these dunes have around high landscape formations such as mountain peaks or volcanoes. In these areas, the dunes had a streamline oriented from west to east, very different from lower altitude dunes that had an east to west orientation. These results showed that on Titan there are two different types of winds that shaped its dunes.
To find out more about the winds on Titan, researchers used a high-pressure wind tunnel to re-create climacteric conditions on this moon. They were surprised to find that the winds there had to be 50 percent higher than previous expected to be able to move the heavy hydro carbonaceous grains from one place to another.
Scientists also solved the two type of winds mystery – it seems that when the Sun changes position in Titan’s sky the winds suddenly reverse direction and start blowing from the west with an unusual high intensity. Researchers say that only these winds can move the sand and shape it into dunes.
Burr and her team reached these findings by using an old wind tunnel built in the 80s to help NASA learn more about how the winds were moving on Venus’ surface. The tunnel was refurbished to simulate winds on Titan that has a much thicker atmosphere and more dense sand.