Nongravitational Effects of Cometary Activity

Nongravitational forces induced by sublimation of volatiles affect the rotational and orbital dynamics of comets. In addition to contributing to the improvement of ephemerides and of rotational models, nongravitational effects can help constrain the regional distribution and temporal evolution of cometary activity, which in turn provides input for the development of thermophysical and dust transport models. We review the progress that has been made in this field thanks to the Rosetta mission and we highlight the open questions.