tidal force

tidal force

A force arising in a system of one or more bodies as a result of differential gravitation: different parts of the system experience different accelerations. This can result in the production of tides and in general terms elongates a body in the direction of a nearby massive body, producing a tidal bulge. The force can alter a body's rotation rate until it is equal to the revolution period: this is true of most natural satellites of the planets, including the Moon, and is the case in some close binary stars, e.g. RS Canum Venaticorum stars. Tidal forces can lead to tidal heating of the interior of a body, and in extreme cases can lead to the disruption of a body.

Collins Dictionary of Astronomy © Market House Books Ltd, 2006