  The interval approach to computation of dynamics of celestial bodies in the
planetary problem has been considered. It is based on the refusal from
idealization of infinitely high resolving capacity of measuring tools, and
forms an absolutely exact algorithm free of round-off error accumulation
effect. The possibilities of the proposed approach are shown by the examples of
Kepler's Problem and the problem of stability of the Solar system major planets
for time interval of 6 billion years. The comparison of the interval and
classical predictions of Kepler's particle location in Kepler's orbit provides
support for the effect predicted by the theory, namely - conservation of the
interval within which the values of difference of interval and classical
coordinates lay with time. The computational results of the Solar system major
planet orbital dynamics agree with the results obtained with the classical
approach.
