  The existence of chaos in the system of Jovian planets has been in question
for the past 15 years. Various investigators have found Lyapunov times ranging
from about 5 millions years upwards to infinity, with no clear reason for the
discrepancy. In this paper, we resolve the issue. The position of the outer
planets is known to only a few parts in 10 million. We show that, within that
observational uncertainty, there exist Lyapunov timescales in the full range
listed above. Thus, the ``true'' Lyapunov timescale of the outer Solar System
cannot be resolved using current observations.
