bscribbler

In the first version of his MC Kepler presents the periods of the planets with values of very high precision. This is well before he has access to Tycho’s data. It is most likely that he gets this information from his praeceptor Michael Maestlin. It is presented by Maestlin in his Epitome on p343 in the 1588 version. In this book he does not derive these values of the periods, just reports them. They are derivable from known information of sidereal and synodic cycles. For example in the case of Mars : 42 sidereal cycles and 37 synodic cycles in 79 years. Or from the time between oppositions, i.e. for Mars 780 days. Copernicus was not aware, as far as I know, of the values that Maestlin and Kepler later know, in such detail as presented in their books. I would like to know when these values were first generated and by whom.