This article explores an Index calculated from the 10 possible synods or inter-planet cycles from Jupiter through to Pluto, simply based on whether the cycle is waxing or waning. The background astronomical and interpretive ideas behind an inter-planetary cycle are given, using the Moon-Sun synod as an archetype. The graph arising from a conflation of all the cycles, calculated for the period 1840 - 2050, is given and briefly discussed, with a few key world events and trends located on significant parts of the graph.