Titan, the largest moon of Saturn, is the only other place in the solar system with flowing rivers and lakes. These rivers, however, are not water but liquid methane. While no tornados are expected on the Saturnian moon due to the dense atmosphere (which makes it difficult to get wind moving), a new study suggests it might still have dust devils.
The Cassini mission detected the effects of rain and dust storms on Titan, but these events were not enough to explain the geological features of the moon, in particular its dusty dunes, which cover 17 percent of its surface. The presence of dust, which is composed of organic material, has been documented on Titan in previous studies, but how it spreads across the moon remained a mystery.
To delve deeper, a team used meteorological models with data collected by Cassini and found it's possible the movement of organic material is due to dust devils. The study is published in Geophysical Research Letters.
"Winds at the surface of Titan are usually very weak. Unless there is a big storm rolling through, there's probably not that much wind, and so dust devils may be one of the main dust transport mechanisms on Titan – if they exist," lead author Brian Jackson, a planetary scientist at Boise State University, said in a statement.
Dust devils form in dry, calm weather conditions. If sunlight warms the surface, some of the surface air starts rising, creating small vortices. Even though Titan is far away from the Sun, it's likely our star still has an influence on the moon's surface.
"When we plug the numbers in for how much dust the dust devil ought to lift based on the wind speeds we see, they seem to be able to lift more dust than we would expect. There may be some other mechanism which is helping them pull this dust – or the equations are just wrong," said Jackson.
Dust devils are found on both Earth and Mars, but we'll have to wait to confirm their existence on Titan. The next mission planned for Titan is not going to reach the Saturnine system until 2034.
“If dust devils are active on Titan's surface, NASA's upcoming Dragonfly mission is likely to encounter them, but dust devils on Titan are unlikely to pose a hazard to the mission,” wrote the authors in the paper. Until then, researchers will continue to dive into the treasure trove of Cassini data. Cassini was a collaborative mission of NASA, ESA, and the Italian Space Agency.