Saturn鈥檚 moon Titan may have strange features called yardangs all over its polar regions. Yardangs are long, perfectly straight ridges that form when erosion wears away strips of soft ground, and they could help us understand Titan鈥檚 complex geology.
Titan鈥檚 upper latitudes are home to hundreds of strange lines that planetary scientists have named bright linear features. Those could be either sand dunes, which astronomers have already observed near Titan鈥檚 equator, or yardangs. The features form in opposite ways 鈥� while dunes are built when sand builds up into parallel mounds, yardangs are carved out from the ground 鈥� but both present as long, straight systems of ridges and troughs, so they can be tough to distinguish from one another.
鈥淚t can be hard to tell from orbit if that鈥檚 what we鈥檙e looking at 鈥� we just see long and straight,鈥� said at Brigham Young University in Utah during the Lunar and Planetary Science Conference in Texas on 12 March.
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Radebaugh and her colleagues used a computer model to compare more than 200 of these features to dunes and yardangs on Earth. Yardangs on Earth and other planets tend to be straighter than dunes, and they appear brighter in radar images. All of the bright linear features on Titan were straighter and 鈥� as their name indicates 鈥� brighter than known dunes, which means they are most likely yardangs.
The fact that the lower latitudes on Titan are dominated by dunes and the upper latitudes by yardangs may help us learn about the different conditions across the icy moon. 鈥淥n Titan, maybe there just isn鈥檛 sand at the high latitudes, or maybe there is material there that is more easily eroded,鈥� said Radebaugh. NASA鈥檚 Dragonfly spacecraft, set to launch to Titan in 2028, should provide troves of new information that will help us figure it out.
