  With the success of the Cassini-Huygens mission, the dynamic complexity
surrounding natural satellites of Saturn began to be elucidated. New ephemeris
could be calculated with a higher level of precision, which made it possible to
study in detail the resonant phenomena and, in particular, the 54:53 near
mean-motion resonance between Prometheus and Atlas. For this task, we have
mapped in details the domains of the resonance with dense sets of initial
conditions and distinct ranges of parameters. Our initial goal was to identify
possible regions in the phase space of Atlas for which some critical angles,
associated with the 54:53 mean motion have a stable libration. Our
investigations revealed that there is no possibility for the current Atlas
orbital configuration to have any regular behavior since it is in a chaotic
region located at the boundary of the 54:53 mean-motion resonance phase space.
This result is in accordance with previous works (Cooper et al. 2015, Renner et
al. 2016). In this work, we generalize such investigations by showing detailed
aspects of the Atlas-Prometheus 54:53 mean-motion resonance, like the extension
of the chaotic layers, the thin domain of the center of the 54:53 resonance,
the proximity of other neighborhood resonances, among other secondary
conclusions. In particular, we have also shown that even in the deep interior
of the resonance, it is difficult to map periodic motion of the resonant pair
for very long time spans.
