On Saturn’s giant moon Titan, it is so cold that water is frozen as hard as granite. And yet there is a complete liquid cycle of methane and ethane. Some scientists wonder whether there could also be life.

A new NASA mission to Titan is not yet on the books, but mission planners are beginning to consider possible scenarios for a visit to the moon in the future. A small, inexpensive lander known as the Titan Mare Explorer (TiME) could launch as early as 2015, arriving in 2022 or 2023.