The orbit pursued by a body moving at precisely the ESCAPE VELOCITY; it takes the form of a PARABOLA (see also ORBIT). In practice an escaping space probe moving away from the Earth will follow a hyperbolic trajectory; a true parabola cannot be attained in practice. Many comets move on orbits which are very nearly parabolic and, since the calculations are easier for parabolas, orbital computations for newly discovered comets tend to be made on the initial assumption that they are following parabolic trajectories.
