Astronomy and Astrophysics – Astronomy
Scientific paper
Sep 1995
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995apj...450..463g&link_type=abstract
Astrophysical Journal v.450, p.463
Astronomy and Astrophysics
Astronomy
39
Convection, Planets And Satellites: Individual Jupiter, Planets And Satellites: Individual Saturn, Radiative Transfer
Scientific paper
Conventional evolutionary models for Jupiter and Saturn, which assume convection throughout the entire planet interior, yield ages of 5.1 Gyr for Jupiter and 2.6 Gyr for Saturn. Even though the discrepancy for Saturn can be explained by the additional energy source due to a phase separation of helium, it seems difficult to reconcile the age of fully convective Jovian models with the age of the solar system, i.e., 4.5 Gyr.
It has been recently shown that these planets are probably not fully convective, but retain a stable radiative window near the surface. We present new evolutionary models for these two planets, which do include the aforementioned possibility of radiative transport in the molecular hydrogen-helium envelope. These calculations yield ages of 4.2 Gyr for Jupiter and 2.4 Gyr for Saturn. We show that the importance of the radiative window was larger in the past than now, so that the ratio of the radiative to the adiabatic gradient in the radiative region increases with time. This speeds up the cooling with respect to a fully adiabatic planet.
Since the interiors of the new Jupiter and Saturn models are significantly cooler than the adiabatic ones, it is likely that immiscibility of helium occurs in both planets. That provides a natural explanation for the observed helium depletion in their atmospheres and the fact that the ages inferred from homogeneous evolution models of these two planets are smaller than the age of the solar system.
Chabrier Gilles
Gautier Daniel
Guillot Tristan
Morel Pascal
No associations
LandOfFree
Effect of Radiative Transport on the Evolution of Jupiter and Saturn does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Effect of Radiative Transport on the Evolution of Jupiter and Saturn, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Effect of Radiative Transport on the Evolution of Jupiter and Saturn will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-824321