The potential for prebiotic chemistry in the possible cryovolcanic dome Ganesa Macula on Titan
New observations of Titan by the Cassini spacecraft suggest the presence of cryovolcanism on the surface. Cryovolcanism has important astrobiological implications, as it provides a means of exposing Titan's organics to liquid water, transforming hydrocarbons and nitriles into more evolved and oxidized prebiotic species. One possible cryovolcano – the 180 km structure Ganesa Macula – resembles the pancake domes seen on Venus by the Magellan spacecraft. To assess the potential of Ganesa Macula for prebiotic chemistry, we estimate its height using radarclinometry and other methods, and calculate the freezing timescale assuming an initially completely liquid dome. Given height constraints of ~200 m to 4 km, we find that liquid water or water–ammonia environments could be sustained in Ganesa Macula for timescales of the order of 102–105 years. These timescales open a window for prebiotic chemistry far wider than can be explored in terrestrial laboratory experiments.(Received April 7 2006)
(Accepted April 28 2006)
(Published Online June 22 2006)
Key Words: cryovolcanism; origin of life; prebiotic environments; prebiotic chemistry; Titan.