Some dunes on Titan – a Saturn moon seen as a chillier version of early Earth – are huge. Scientists now have suspicions about what's going on, but they don't yet know how Titan's version of sand formed.
U.S. / Japan ASTER Science Team / GSFC / METI / ERSDAC / JAROS / JPL-Caltech / NASA
Radar images from NASA's Cassini orbiter reveal that the size and spacing of the dunes change depending on the latitude of the dune fields and the elevation of the land on which they sit. The findings may help uncover the distribution of winds on the moon and yield clues to help resolve a long-standing debate over how and where the sand itself formed, according to the team reporting the results in the January issue of the journal Icarus.
"Understanding how the dunes form as well as explaining their shape, size, and distribution on Titan's surface is of great importance to understanding Titan's climate and geology," notes Nicolas Altobelli, Cassini project scientist with the European Space Agency, one of NASA's partners in the mission, in a statement.
Titan, Saturn's largest moon and the second largest in the solar system, has been a prime target for Cassini's instruments since the craft began touring Saturn and its moons in June 2004.
Formed mainly of water ice and rock, Titan hosts lakes of liquid hydrocarbons. When it rains on Titan, it drizzles liquid methane, rather than water.