According to two new studies conducted by the scientists at the University of Tennessee, Knoxville, the giant sand dunes on Saturn’s moon Titan have been created by rare bursts of wind blowing westward. The sand dunes of Titan reach a height of more than 300 feet (91 meters) and have puzzled scientists for many years since they seem to form in the opposite direction as Titan’s steady east-to-west winds.

“This work highlights the fact that the winds that blow 95 percent of the time might have no effect on what we see,” Devon Burr, a planetary scientist at the University of Tennessee, Knoxville, and lead author of one of the papers, said in a statement.

Burr,  and her colleagues conducted their research in a wind tunnel built in the 1980s for studying the physics of wind-blown sand on Venus. There, they tried to replicate the conditions on the surface of Titan that would influence the formation of dunes, such as a lower gravity and a thicker atmosphere than Earth’s.

“It was a bear to operate, but Dr. Burr’s refurbishment of the facility as a Titan simulator has tamed the beast. It is now an important addition to NASA’s arsenal of planetary simulation facilities,” John Marshall, of the SETI Institute, and a co-author on the new research, said in the statement.

The researchers mentioned that the dunes on Titan are not made of the kind of sands found in the deserts on Earth, but a more viscous material. They don’t know exactly what it is but speculate it be a compound made up of hydrogen and carbon. The hydrogen-carbon material may coat particles of water ice, the scientists mentioned.