Mystery of Titan's Windswept Dunes Solved
The mystery of Titan's windswept dunes is finally solved, thanks to a research team at the University of Tennessee, a new study says.
Saturn's largest moon is a peculiar place, with lots of enigmas in its environment and geography. Unlike any other moon, it has a dense atmosphere, not to mention rivers and lakes made up of components of natural gas, such as ethane and methane. Titan's famous disappearing and reappearing "magic island" in the sea known as Legeia Mare is yet another puzzle scientists have struggled to explain in the past.
But possibly the most head-scratching phenomenon of all are the moon's windswept dunes, towering hundreds of feet high, and spanning more than a mile wide and hundreds of miles long. However, previous research has suggested that Titan only experiences light breezes, rather than the gushing winds needed to create such impressive dunes.
Now, a study published in the journal Nature contradicts this theory, painting a much windier picture of the moon.
"It was surprising that Titan had particles the size of grains of sand - we still don't understand their source - and that it had winds strong enough to move them," lead researcher Devon Burr said in a statement. "Before seeing the images, we thought the winds were likely too light to accomplish this movement."
The said images came from the Cassini spacecraft and were taken a decade ago, and showed never-before-seen dunes created by particles not previously known to have existed.
To add more intrigue to the story, the most puzzling part was the shape of the dunes - indicating winds blew from east to west. But the streamlined appearance of the sand dunes around obstacles like mountains and craters suggested winds blowing in the exact opposite direction.
So Burr and her colleagues used a NASA high-pressure wind tunnel to recreate Titan's surface conditions, accounting for 23 different varieties of sand. They found that the minimum wind on Titan has to be about 50 percent faster than previously thought to move the sand.
"If the predominant winds are light and blow east to west, then they are not strong enough to move sand," Burr said. "But a rare event may cause the winds to reverse momentarily and strengthen."
"The high wind speed might have gone undetected by Cassini because it happens so infrequently," she added.
So while the famous Titan still holds many mysterious, this is one that scientists can finally say they've solved.
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