Online Astronomy eText: The Planets
The Rotation of Jupiter

      Because Jupiter has no solid surface, and all that we see is cloud features, different parts of the planet appear to rotate at different rates, depending upon the circulation patterns in the atmosphere. The rotation period listed in the discussion of the planets' Rotation and Day Length is based on the radio emissions of the planet, which are believed to be linked to the rotation of the planet's magnetic field, and through that, to the rotation of the "body" of the planet.