Wrong   I removed this from the article  This is not only informal it is wrong  Wrong because Newton by employing three orbital points positions for any planet  obtained from John Flamsteed See David H and Stephen P H Clark Newtons Tyranny The Suppressed Scientific Discoveries of Stephen Gray and John Flamsteed W H Freeman and Co    could produce an equation describing the motion of its orbit  This was true all except for the two outermost planets known then whose orbits even today have to be constantly updated  I dont see how this makes the statement that preceded it wrong