  Asteroids and comets dissipate energy when they rotate about the axis
different from the axis of the maximal moment of inertia. We show that the most
efficient internal relaxation happens at the double frequency of body's
tumbling. Therefore the earlier estimates that ignore double frequency input
underestimate the internal relaxation in asteroids and comets. We show that the
Earth seismological data may poorly represent acoustic properties of asteroids
and comet as internal relaxation increases in the presence of moisture. At the
same time owing to non-linearlity of inelastic relaxation small angle nutations
can persist for very long time spans, but our ability to detect such
precessions is limited by the resolution of the radar-generated images.
Wobbling may provide valuable information on the composition and structure of
asteroids and on their recent history of external impacts.
