Mars’ gravitational pull may influence Earth’s long-term climate cycles, study finds

Mars may exert a measurable influence on Earth’s long-term climate cycles through gravitational interactions that alter our planet’s orbit and tilt, according to research published Sunday in Publications of the Astronomical Society of the Pacific. The study used advanced simulations to demonstrate that Mars plays a key role in modulating Milankovitch cycles—periodic variations in Earth’s orbital parameters that affect solar energy distribution over thousands to millions of years.

Impact on Key Orbital Cycles

Researchers tested how changes in Mars’ mass would affect Earth’s orbital eccentricity, axial tilt (obliquity), and other Milankovitch parameters. While the 405,000-year eccentricity cycle—primarily driven by Venus and Jupiter—remained stable, shorter eccentricity cycles linked to Mars (around 100,000 years) grew longer and more pronounced as Mars’ mass increased. Notably, the 2.4-million-year “grand eccentricity cycle” disappeared entirely in simulations where Mars’ mass approached zero, indicating this cycle depends directly on gravitational pull from the Red Planet.

Broader Implications for Planetary Science and Paleoclimate

The findings suggest that Mars has played a more substantial role in shaping Earth’s deep-time climate forcing than previously recognized. This interplanetary connection could help refine models of past climate shifts, such as Ice Age cycles, and improve understanding of how orbital mechanics drive long-term environmental change. Additionally, the research proposes that similar orbital signatures detected in exoplanet systems could allow astronomers to infer the masses of neighboring planets.

Revealing the Gravitational Web of the Inner Solar System

The study underscores the complex gravitational interplay among the inner planets, where even a relatively small world like Mars can leave a discernible imprint on Earth’s orbital behavior over geological timescales. This adds a new dimension to the study of astroclimatology—how celestial mechanics influence planetary climates—and highlights the value of dynamic orbital modeling in both understanding Earth’s history and characterizing distant planetary systems.