“Wait a second, are those dunes?” Scorch peered through the window. The four Mysticals were in Orak’s tempus machine. They were flying right over Jupiter’s moon Io.

“Yes,” Orak replied and added, “A team of scientists has found out how dunes form on Io. Would you like to know more about it?”

“Yes, please,” Felix said.

“Io is the third-largest of the four Galilean moons. Galilean moons were discovered by Galileo Galilei, an Italian astronomer. Io has more than 400 active volcanoes. Due to that, its surface is a mix of lava that is solidified, flowing lava streams, and snows of sulfur dioxide.

Previous scientists also found something curious on Io’s surface, something that looked like a dune. But Io has no strong winds. It has weak winds. It also has an icy surface. Sand dunes on Earth are created when strong wind deposits sand on top of each other till a mound is formed. So, the scientists thought the features couldn’t be dunes,” Orak said.

“But now, a team of scientists concluded that they are dunes! But the word ‘dune’ might need a new definition,” Orak said.

“What do you mean?” Verum said.

“The team experimented by copying the physical processes that control grain (very small piece of something) motion on the surface. They used mathematical equations to copy the forces acting on a single grain of basalt rock (volcanic rock) or frost to calculate its path. When lava flows into the sulfur dioxide beneath Io’s surface, it creates a fast-moving vent. It can move a lot of grains and form large features such as dunes!” Orak said.

“So, it’s not just strong winds that can form the dunes?” Scorch said.

“Seems like it,” Orak said.

“Once the team knew how dunes could form on Io’s surface, they compared the results of their experiment to the photos of Io’s surface. The photos were taken by the spacecraft Galileo. They matched!” Orak said.

“And the mystery of the incredible Io’s dunes is solved!” Verum declared.