Mars influence on the Milankovitch cycles:
Anton Petrov’s summary:
I imagine there is a significant potential interaction over long time scales due to lunar position and orbital plane. If Mars has a measurable impact on Earth, the reverse must be true as well, and Luna is the primary anomaly IMO.
Luna is ~1% the mass of earth so I assume it would contribute very little to orbital perturbations in the solar system.
But it is a changing 1.23% on the same plane. Both respective planets have no significant satellites. Venus spins wonky. I’m not saying any of it is related, but it is curious.
Venus is loosely around solar lap 20M, Earth 12M, Mars 6.5M in the last 4.5 billion years. How many 1% differences stack in patterns before there is a problem?
Two more variables that are going to affect the number of encounters are when the “final” orbits of the inner planets were established (the Nice model suggests there was much disruption early on) and that Mars’ orbit is very elliptic so it’s rarely lining up at its closest approach, which is still pretty far. If anything we’d more likely see some correlation between Earth and Venus if there is any.