Titan is the Saturn’s largest moon. In 2004, NASA’s Cassini spacecraft began exploring the moon.
The greatest discovery of the spacecraft was the field of dunes which nearly covered 15 percent of the Titans surface along the equator.
These dunes are the largest in the solar system.
These are dark and massive dunes made of sand which is composed of carbon and hydrogen. They are more than 18 to 31 miles or 30 to 50 kilometer long and 330 feet or 100 meters high.
Until here it sounds good but the mystery the scientists want to solve is that these dunes on the surface of the moon are growing eastward while the winds at the equatorial latitudes blow westward, so they are puzzled by the behavior of the dunes.
Scientist found that the winds blow eastward but at an altitude above about 3 miles or 5 km which made them believe that they can solve this mystery somehow even though the winds are very far above the dunes.
Now the findings of the rare methane storms could possibly solve the mystery of sand dunes growing eastward.
“Clouds and storms are rare on Titan, they were not expected to have an impact on dunes,” said Benjamin Charnay, a planetary scientist at the Dynamic Meteorology Laboratory in Paris, who led the study.
Titan is having special characteristics which no other moon in the solar system posses. Titan is the only moon with thick atmosphere and the atmosphere is composed of nitrogen and traces of methane which can form into clouds. During the equinox, when the day and night are equal, Titan experiences violent, huge methane storms in tropical region around its equator.
Computer models of weather on Titan revealed that the methane clouds can reach altitudes of 15.5 miles or 25 kilometers, where the winds blow eastward. The methane storms can produce downdrafts that flow eastward on strong gusts after they reach Titans surface. These eastern gusts can reach up to 22 mph or 36 km/h which is 10 times faster than the usual winds close to the surface.
These storm gusts explain the shape, size and spacing and eastern growth of the Titans dunes.
By studying the dune formation of Titan, scientist can also learn more on dune formation on Earth.
