Overview
- Removing Mars from the models erased two Milankovitch rhythms on Earth, one near 100,000 years and another around 2.3–2.4 million years.
- A 430,000‑year eccentricity cycle driven by Venus and Jupiter persisted regardless of Mars’ presence.
- Increasing Mars’ mass in the simulations shortened the affected cycle periods and reduced the rate of change in Earth’s axial tilt, implying a stabilizing effect on obliquity.
- The study ties Mars‑driven dynamics to a ~2.4‑million‑year “Grand Cycle” seen in deep‑sea sediment records, suggesting a link to stronger shifts between glacial and interglacial states.
- The peer‑reviewed work by UC Riverside researchers, published December 18, 2025 in Publications of the Astronomical Society of the Pacific, also flags implications for climate stability on Earth‑like exoplanets.