Dieter Egger,
1997-02-19
Almost the same applet like "Orbit Elements and State Vector" is presented here. But you may choose the orbiting body to be a planet or the earth's moon. The corresponding orbital elements (mean elements for the epoch of the actual day at noon) are being computed. On the right hand side the corresponding state vector is shown. Reference system is the ecliptical system with the Sun as center point (except for the Moon when the Earth is the origin of the reference system) and the x-axis pointing to the (mean) vernal equinox. GM represents gravitational constant times mass of the central body (Sun or Earth).
The accuracy is limited because no disturbances between the planets are taken into account. Only time dependency to the third order is used to evaluate the orbital elements. You may like to read about this in Meeus's nice booklet "Astronomical Formulae for Calculators".
Pluto's orbit is determined by osculating orbital elements of July 11, 1997.
Enjoy the applet.
Dieter Egger,
1997-02-19