Improved Ephemerides of Pluto

The history of the Pluto ephemerides created at JPL is given. The uncertainties of present and possible future ephemerides are illustrated, and it is shown how rapidly the error grows for any present-day ephemeris of Pluto which is extrapolated into the future - tens of thousands of kilometers after only a decade. Continuing the observations into the future will not only reduce the extrapolation time but time will provide a substantial improvement to the ephemeris itself.