Periodic and quasiperiodic attractors for the spinorbit evolution of Mercury with a realistic tidal torque
Abstract
In this paper, we make a detailed study of the spinorbit dynamics of Mercury, as predicted by the realistic model that has been recently introduced in a series of papers mainly by Efroimsky and Makarov. We present numerical and analytical results concerning the nature of the librations of Mercury's spin in the 3:2 resonance. The results provide evidence that the librations are quasiperiodic in time, consisting of a slow oscillation, with an amplitude of order of arcminutes, superimposed on the 88d libration. This contrasts with recent astronomical observations and hence suggests that the 3:2 resonance in which Mercury has been trapped might have been originally described by a largeamplitude quasiperiodic libration that, only at a later stage, with the formation of a molten core, evolved into the smallamplitude libration that is observed today.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 July 2017
 DOI:
 10.1093/mnras/stx809
 arXiv:
 arXiv:1703.01189
 Bibcode:
 2017MNRAS.469..127B
 Keywords:

 celestial mechanics;
 planets and satellites: dynamical evolution and stability;
 planets and satellites: individual: Mercury;
 Mathematics  Dynamical Systems;
 Astrophysics  Earth and Planetary Astrophysics;
 Mathematical Physics;
 Mathematics  Classical Analysis and ODEs
 EPrint:
 32 pages, 8 figures, 5 tables