Structure of Titan’s crust and mechanisms for releasing methane into Titan’s atmosphere. Titan’s upper crust is likely composed of MCH, which, when thermally destabilized, release methane as gas (inset). Different internal processes, such as convective upwelling (and also diapiric activity), are shown in the main figure. Under certain conditions, these intrusions cause destabilization of the MCH, releasing the methane trapped within. The image on the right shows how methane can work its way through cracks in the solid MCH (in part caused by the diapir or other intrusion) above the destabilized layer toward the surface. Methane could also form a liquid layer beneath a layer of organic material. Any methane reaching the surface replenishes the methane lost through photolysis and atmospheric escape. (Figure credit: Katherine Park, JPL).