Most astronomers believe that the massive moons of Jupiter, including Io, Europa, Ganymede and Callisto, were born from a large gaseous disk that surrounded the planet during its formation. However, until now, the processes that brought smaller moons, particularly those around Uranus, Neptune and Pluto, into existence has remained a mystery. Aurélien Crida and Sébastien Charnoz now suggest that most moons in the solar system were born from massive ring systems that once surrounded the planets.
Read more about this research from the 30 November issue of Science here.
[Image courtesy of Frederic Durillon | animea; click the image for more information.]