Massive dunes on Saturn's biggest moon, Titan, may have been formed due to violent methane storms.
Scientists suggest that Titan is the nearest Earth-like celestial object in the solar system. The winds on Titan are near to the surface and blow from east to west, similar to the trade winds on Earth. However, the giant surface dunes on Titan point toward the east.
While previous theories explain the reason of the east pointing winds, researchers at the University of Washington (UW) have a new explanation. Previous models did not include methane clouds when explaining the reason for the dune's direction. However, now researchers believe that methane clouds may hold the clues for the formation of the dunes.
Researchers have taken the help of computer models, which enabled them to understand the direction of the dunes on the moon. The scientists explain that methane storms on Titan are a rare occurrence but produce eastward winds, which are comparatively stronger than westward winds.
The methane storms may reach as high as 22 miles per hour, which is about 10 times stronger and faster than the westward winds. While the methane storms are faster, they realign the dunes to point toward the east.
"These fast eastward gusts dominate the sand transport, and thus dunes propagate eastward," says Benjamin Charnay, postdoctoral researcher at UW.
The Cassini-Huygens, an unmanned spacecraft, has been observing Saturn and its moons for over a decade. Charnay suggests that observations from the spacecraft reveal that Titan's atmosphere above five miles over the surface rotates faster than the surface and methane storms produce downward winds that help in realigning the dunes.
Christiaan Huygens, a Dutch scientist, discovered Titan in 1655 and since then, the moon has intrigued many astronomers. More than 98 percent of Titan's atmosphere is made up of nitrogen, and a majority of the balance is made of methane.
The gravity on Titan is about one-sixth of that found on Earth, and the air density is about four to five times higher than our planet, which means that flight will be relatively easy for visiting spacecraft. The Huygens probe, which was launched along with Cassini, landed on Titan's surface in 2005 and, since then, has been sending information to scientists on Earth.
Charnay suggests that direct observation made by Cassini may help in confirming his theory about the dunes on Titan.
