There are many mysteries about the planet Saturn and its entourage of moons. One, of course, is how its spectacular ring system was formed.
Recently, scientists showed that the answer to that mystery may be tied up in another.
A decade ago, measurements of the mass distribution of Saturn by the Cassini probe suggested that its mass is slightly more concentrated towards its centre than expected.
This could be explained if Saturn once had an extra moon, which astronomers called Chrysalis.
Astronomers thought that this missing moon could have broken up to form the rings after an encounter with Titan, Saturn’s largest moon (and the second-largest moon in the Solar System, after Jupiter’s Ganymede).
