In cryovolcanism, volatiles such as water, ammonia or methane, are spewed out instead of molten rock.
Titan has an atmosphere rich in organic carbon-based compounds and has clouds and rains of liquid methane that mimic Earth's water cycle. Its landscape is remarkably Earth-like with dunes and lakes, erosion due to weathering and tectonic-like features.
Astronomers believe that beneath its icy surface there is an ocean of liquid water, possibly mixed with ammonia. The low number of impact craters seen on Titan suggests that the surface is relatively young and is therefore dynamic and active.
Anezina Solomonidou, of the Observatoire de Paris and National and Kapodistrian University of Athens, said that these features, plus a need for a methane reservoir and volcanic activity to replenish the methane that they detected in the atmosphere, is compatible with the theory of active cryovolcanism on Titan.
Solomonidou and colleagues investigated the potentially cryogenic regions of Tui Regio, Hotei Regio and Sotra Patera using Cassini's Visual and Infrared Mapping Spectrometer (VIMS).
She said that they were able to penetrate the atmosphere with VIMS and view any changes in these surface features. Interestingly, the albedo (brightness) of two of the areas has changed with time.
She added that Tui Regio got darker from 2005 to 2009 and Sotra Patera - the most favorable cryovolcanic candidate on Titan - got brighter between 2005 and 2006.
--ANI (Posted on 15-09-2013)