Pluto Resonance
The dwarf planet Pluto is host to at least five known moons - Charon, Nix, Kerberos, Styx and Hydra.
Research has shown than three of these satellites - Styx, Nix and Hydra - are tied together by a
three-body resonance, reminiscent of that which links the Galilean moons of Io, Europa and
Ganymede. The five Plutonian moons have orbital periods in the ratio of 1:3:4:5:6. This means, for
example, that the period of the outermost moon is six times the period of Charon, the innermost one,
and so on. However, the ratios are not entirely precise, because of chaos in the system. This
conceptual illustration uses a clockwork framework linking the orbits of the moons to show that they
are intimately connected to each other.
This image was commissioned for the
front cover of
Nature, 4 June 2015.