Why the Earth and Titan?

Well, there are good reasons to consider the Earth and Titan in one category. In a nutshell, Titan is the only world that we know which looks similar to the Earth. Certainly, the temperature is different, and surface chemistry is exotic, but the overall picture: mountains shaped by erosion, river valleys meandering through the landscape, shorelines, lakes and seas, clouds and rain - all is there.

It seems certain that we are about to witness the birth of a new science. In principle, it will be a science parallel to hydrology, so it is only fitting that it should be called methanology. If we look for further parallels, the hydrological cycle will become a methanological cycle on Titan, and hydrogeology could easily become methatitanology...

Anyway, let us look for some comparisons: