418 Encyclopedia of the Solar System
Saturn’s innermost C-ring may be produced by oscillation
modes of the planet. Further spacecraft observations are
required to confirm this hypothesis, however, and work is
currently underway analyzing new data from theCassini
spacecraft.
Definitive detection of oscillations of any jovian planet
would first serve to accurately determine the core size and
rotation profile of the planet. Because such determinations
would remove two sources of uncertainty surrounding the
interior structure, more information could then be gleaned
from the traditional interior model constraints. Seismology
might also help to constrain more accurately the location
of the transition from molecular to metallic hydrogen in
Jupiter’s interior. If so, seismology may ultimately provide
the tightest constraints on the hydrogen equation of state
and interior structure of jovian planets.
Together with a refined understanding of the interiors
of our solar system’s giant planets, additional understanding
of giant planet interiors will come from extra-solar planets.
Determinations of the radii of transiting extra-solar planets
will allow us to build up a statistical sample to learn how
the radius of planets change as a function of mass, age, the
amount of heavy elements available in the system (which
can be estimated from spectra of the parent star), and the
amount of irradiation the planet receives from its parent
star. The interiors of giant planets will likely yield many
additional surprises as more extra-solar planets are found.
[SeeExtra-SolarPlanets.]Bibliography
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