Pluto’s moons rotate chaotically

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Data from the Hubble Space Telescope has determined that two and maybe more of Pluto’s moons have chaotic rotations.

In a surprising new study, it has been found that two of Pluto’s moons, Nix and Hydra, are in a chaotic rotation. This means that an observer on Pluto would not see the same face of the moons from one night to the next. For visitors on the moons themselves, things would get even more confusing, as every day would be a different length to the one that preceded it. The other two moons studied, Kerberos and Styx, will likely be found to be chaotic too, pending further study.

This would also mean that you would not know where on the horizon the sun or Pluto would rise each day.

This information was gathered partly to help New Horizons prepare for its July 14 fly-by.


  • Expecting a slew of sci-fi stories featuring the Pluto system post- New Horizons.

  • Gealon

    It’s not really a surprise considering Pluto/Charon’s gravitational field isn’t exactly muscular. The other four moons are likely just rocks/ice with just enough pull exerted on them to remain in orbit but not enough to become tidally locked.

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