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.
Titan is the largest moon of Saturn. It was discovered in 1655 by Christiaan Huygens, and was the 6th moon to be discovered after our own, and the 4 Galilean moons around Jupiter. It is the second largest moon in the Solar System, and orbits Saturn at an average distance of roughly 1.2 million kilometers. Although it is larger than Mercury, it has less than half as much mass. It also has a thick, cloudy atmosphere, and until a few decades ago, that was almost all we knew.
