🌍 The lasting influence of Mars on Earth's climate

Our neighbor Mars would hold a significant influence over Earth's climate. New research indicates that its gravity durably alters Earth's orbit and tilt, reshaping climatic conditions over millennia.

Our planet's long-term climate changes are often linked to Milankovitch cycles, alterations in orbit and rotational axis caused by the gravitational pull of other celestial bodies. Traditionally, Venus and Jupiter were seen as the main actors, but new simulations reveal that Mars plays a much more substantial role than previously estimated.


Researchers conducted detailed simulations of the Solar System to measure the impact of each planet. Stephen Kane from the University of California, Riverside, and his colleagues observed that Mars's influence is decisive for certain climate cycles. By removing Mars from the models, two major cycles disappear, demonstrating its importance.

These cycles notably affect the eccentricity of Earth's orbit and the precession of the equinoxes, with periods of 100,000 and 2.4 million years. The simulations show that Mars's mass directly influences the duration of these cycles; a higher mass shortens them, while its absence eliminates them entirely.

Earth's tilt, which fluctuates between 21.5 and 24.5 degrees, is stabilized by this interaction. Until now, this role was attributed to the Moon, but Mars also helps prevent excessive oscillations. This observation could change how we search for habitable planets elsewhere.

For astronomers, this means an Earth-like planet could benefit from a stable climate thanks to the presence of a modest external body. As Kane reports in Publications of the Astronomical Society of the Pacific, planetary systems containing distant planets could offer conditions favorable to life.