Saturn’s moon, Titan, has long intrigued researchers. Its features are very non-moon like. Titan is known for its dense atmosphere, rivers and lakes comprised of natural gases. One other feature has had researchers scratching their heads. Windswept dunes rising hundreds of yards above the ground and stretching for hundreds of miles.
Previous data suggests Titan has just a light breeze at best. But, researchers knew there had to be more wind after seeing pictures of Titan’s dunes snapped ten years ago by the Cassini spacecraft.
Top image shows dunes on Titan compared to sand dunes on Earth (bottom image).
Researchers led by Devon Burr, a professor at the University of Tennessee, used a high-pressure wind tunnel to mimic Titan’s surface conditions. Burr and her team simulated Titan’s tense atmosphere, flipped on the wind tunnel fan and watched how the sand shifted. 23 different types of sand were used in order to gauge what could be happening on Titan.
After two years of modeling, the team says the minimum wind required to create the dunes has to be 50% faster than what previous data has suggested.
“We discovered that movement of sand on Titan’s surface needed a wind speed that was higher than what previous models suggested.”
Burr and her team also have a potential answer for the biggest question surrounding the dunes. Data from Cassini showed winds blew from east to west on Titan’s surface. Yet, the dunes appear to form by winds moving west to east.
Burr believes a “rare event may cause the winds to reverse momentarily and strengthen.”
This ‘rare event’ would happen twice a Saturn year (about 30 Earth years) according to atmospheric models. The reversal in winds occurs as the sun crosses over the equator.
“The high wind speed might have gone undetected by Cassini because it happens so infrequently.”
Long term study of Titan’s wind patterns would give researchers a better idea on how strong these reversal winds potentially get.
Image credit: NASA