On the influence of gravitational radiation on a gyroscope

We calculate the precession of a gyroscope at rest in a Bondi spacetime. It is shown that, far from the source, the leading term in the rate of preces sion of the gyroscope is simply expressed through the news function of the system, and vanishes if and only if there is no news. Rough estimates are p resented, illustrating the order of magnitude of the expected effect for di fferent scenarios. It is also shown from the next-order term (1/r(2)) that non-radiative (but time-dependent) spacetimes will produce a gyroscope prec ession of that order, thereby providing 'observational' evidence for the vi olation of Huygens principle.