[PatrickHenry]

I think the overall point is that you could, if you wanted to, select earth as the frame of reference, and plot everything's movement from that perspective. But that's just the old Ptolemy system. My understanding is that it works, and you could probably do the computations needed to send probes to the other planets that way, but it's devilishly complicated.

[RadioAstronomer]

I think the overall point is that you could, if you wanted to, select earth as the frame of reference, and plot everything's movement from that perspective

Indeed you can :-)

My understanding is that it works, and you could probably do the computations needed to send probes to the other planets that way, but it's devilishly complicated.

Actually we use stellar navigation and a solar orbit to accomplish that. We place the spacecraft into a solar orbit that intersects the planets orbit path. It just has to be such that the planet is there when the probe gets there. What is also interesting is that the planet is not always there the first time around. Sometimes it takes two solar orbits by the spacecraft before they meet. The Magellan did that.