31
Titan, the largest moon of Saturn, looks more Earth-like on its surface than any other place in the Solar System. With its thick atmosphere and liquid methane rain, it has lakes, rivers, sand dunes and seas. But appearances can be deceiving and in other ways, Titan is in fact a very alien world. One baffling difference, recently discovered, is that Titan’s rivers do not seem to form deltas when they reach the sea.
