A Proposed Mechanism for the Formation of Protocell-like Structures on Titan

Based on present knowledge of atmospheric composition, a mechanism for the natural formation of vesicles in the lakes of Titan is proposed. It involves precipitation-induced spray droplets coated by a monolayer of amphiphiles. On interaction with the monolayer on the lake’s surface, bilayer membranes are being formed that encapsulate the liquid phase of the original droplet. The resulting vesicles develop thermodynamic stability by continuous compositional selection of various types of amphiphiles in a dynamic equilibrium, leading to an optimized vesicle stability. Different populations of stable vesicles may compete, initiating a long-term evolution process that could eventually result in primitive protocells. The existence of any type of vesicles on Titan would prove that early steps towards increasing order and complexity have taken place, which represent the necessary precondition for abiogenesis. A valid analytical approach could involve a laser device with combined light scattering analysis and surface enhanced Raman spectroscopy. It would allow for very sensitive detection of amphiphiles as well as for the observation of dispersed vesicles.