Snow on Saturn's moon

Astronomers say that the surface of Saturn's moon Titan may be covered by a layer of "snow".

- 

Titan is an icy world whose surface is completely hidden by its thick golden atmosphere.

The haze makes it hard to see the surface, but experts have now analysed radar (a detection system that uses radio waves) signals recorded by a spacecraft called Cassini, which orbited Saturn between 2004 and 2017.