Dear friends of XEphem,
I would like to have my Bachelor students estimate the orbital period of Mars using only data from XEphem-simulated ground-based observations. I mean, from Sky view, from the Data table... and of course not from the Solar system view. I feel there should be a way to do this by estimating the interval between two dates at which the Sun, Earth and Mars are aligned but I am not sure how to define this configuration from XEphem data. Could I simply select one "fixed star" of the ecliptic plane and wait for Mars to come again to this position as seen from Earth?
A rough estimate would be sufficient but a precise method is welcome if simple enough for me and my non-specialist students! If it's easier with any other planet, let me know...? Any help would be highly appreciated!
Yours,
Maxime
