Obliquity evolution for Earth over the next million years (upper left), from our secular model. Compare to Figure 10, top panel, in Laskar et al. (1993a). Also shown is the obliquity evolution for Earth without the Moon (lower left), from our secular model. Compare to Figure 11 top panel, in Laskar et al. (1993a). On the right, we have the obliquity evolution for Mars backwards in time with the secular orbital solution (upper right) and coupling DISTROT and HNBody (lower right).