{"id":800111,"date":"2026-01-14T07:26:28","date_gmt":"2026-01-14T12:26:28","guid":{"rendered":"https:\/\/spaceweekly.com\/?p=800111"},"modified":"2026-01-14T07:26:28","modified_gmt":"2026-01-14T12:26:28","slug":"earths-ice-ages-shaped-by-tiny-tugs-from-mars","status":"publish","type":"post","link":"https:\/\/spaceweekly.com\/?p=800111","title":{"rendered":"Earth\u2019s ice ages shaped by tiny tugs from Mars"},"content":{"rendered":"
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\nNASA\u2019s Curiosity rover captured this image showing Earth as a tiny dot of light seen from the surface of Mars. Our planet Earth shines more brightly than any star in the Martian night sky. But can Mars affect Earth\u2019s climate? Scientists from UC Riverside are saying that tiny tugs on Earth from Mars have had a big effect on Earth\u2019s ice ages. Wow! Image via NASA.<\/figcaption><\/figure>\n
EarthSky\u2019s 2026 lunar calendar shows the moon phase for every day of the year. Get yours today!<\/p>\n
Earth\u2019s ice ages shaped by tiny tugs from Mars<\/h3>\n
You wouldn\u2019t think that Mars could have an influence on Earth\u2019s ice ages. Mars is only half the size of Earth. It has just 1\/10 of Earth\u2019s mass. Plus, depending on where they are in orbit around the sun, the two worlds can be separated by tens to hundreds of millions of miles. Still, scientists at the University of California Riverside said on January 12, 2026, that small gravitational tugs from Mars help shape the cycles that drive long-term climate patterns on Earth.<\/p>\n
Scientists had long thought Mars\u2019 gravitational pull was too weak to impact Earth\u2019s climate. But some recent studies have suggested otherwise. So Stephen Kane, a professor of planetary astrophysics at UC Riverside, decided to run some computer models to see for himself. Kane said: <\/p>\n
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I knew Mars had some effect on Earth, but I assumed it was tiny. I\u2019d thought its gravitational influence would be too small to easily observe within Earth\u2019s geologic history. I kind of set out to check my own assumptions.<\/p>\n<\/blockquote>\n
Kane and colleagues published their study in the peer-reviewed journal Publications of the Astronomical Society of the Pacific<\/em> on December 18, 2025.<\/p>\n
The cycles that shape our climate<\/h3>\n
How much solar energy Earth receives is what determines our climate. And there are three cycles, called Milankovitch cycles, that affect how much radiation Earth receives from the sun. These cycles are based on orbital mechanics. NASA describes the three Milankovitch cycles as:<\/p>\n
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eccentricity<\/strong>, or the shape of Earth\u2019s orbit obliquity<\/strong>, or the angle Earth\u2019s axis is tilted with respect to Earth\u2019s orbital plane precession<\/strong>, or the direction Earth\u2019s axis of rotation is pointed<\/p>\n<\/blockquote>\n
Kane created computer simulations of how these cycles change over tens of thousands to millions of years. He ran the simulations showing the whole solar system, and then played with the size of Mars, increasing it and decreasing it, including removing it altogether. And for two of the cycles, the team found that removing Mars made the two cycles vanish.<\/p>\nEarth\u2019s orbit around the sun, in contrast to the orbit of Mars. Image via NASA\/ UC Riverside.<\/figcaption><\/figure>\n
Mars\u2019 impact on our climate<\/h3>\n
The two cycles that Mars\u2019 presence impacts are Earth\u2019s eccentricity and obliquity. These two characteristics influence how much sunlight different areas of Earth get.<\/p>\n
Let\u2019s take a closer look at how Mars influences the tilt (obliquity) of Earth. Currently, Earth has a tilt from straight up and down of about 23.5 degrees. Kane said:<\/p>\n
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As the mass of Mars was increased in our simulations, the rate of change in Earth\u2019s tilt goes down. So increasing the mass of Mars has a kind of stabilizing effect on our tilt.<\/p>\n<\/blockquote>\n
In other words, if Mars were larger, it would dramatically change the pattern of ice sheet growth and retreat on Earth.<\/p>\n
Mars\u2019 pull on Earth\u2019s eccentricity \u2013 or how circular or stretched out our orbit is around the sun \u2013 has an impact, too. In a grand cycle that lasts 2.4 million years, Mars\u2019 gravitational pull slightly shifts Earth\u2019s path around the sun. <\/p>\n
Earth\u2019s ice ages<\/h3>\n
Earth has survived at least five major ice ages. In fact, we\u2019re in one now. An ice age is when there are permanent ice sheets at the poles. And sometimes during the ice ages, glaciers can advance and cover much of the globe. It was only about 11,000 years ago that the last major ice sheet \u2013 the Wisconsin glaciation \u2013 retreated after covering much of North America.<\/p>\n
The Milankovitch cycles have helped to bring about and also end these different ice ages. And now we know that Mars plays a role in these cycles as well. Kane mused: <\/p>\n
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Without Mars, Earth\u2019s orbit would be missing major climate cycles. What would humans and other animals even look like if Mars weren\u2019t there?<\/p>\n<\/blockquote>\n
Impacts on other solar systems<\/h3>\n
The computer simulations suggest that life on distant worlds could even be influenced by small, outer, lifeless planets. Kane said:<\/p>\n
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When I look at other planetary systems and find an Earth-sized planet in the habitable zone, the planets further out in the system could have an effect on that Earth-like planet\u2019s climate. <\/p>\n<\/blockquote>\n
Our solar system and neighboring planets have even more of an impact on our lives than we might have first thought.<\/p>\n
Bottom line: Computer simulations show the presence of Mars affects the cycles that cause Earth\u2019s ice ages and climate changes.<\/p>\n
Source: The Dependence of Earth Milankovitch Cycles on Martian Mass<\/p>\n
Via UC Riverside<\/p>\n
Read more: Gravity between Mars and Earth drives climate and currents<\/p>\n
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Kelly Kizer Whitt<\/h4>\n
View Articles\n <\/p><\/div>\n
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About the Author:<\/h6>\n
Kelly Kizer Whitt – EarthSky\u2019s nature and travel vlogger on YouTube – writes and edits some of the most fascinating stories at EarthSky.org. She’s been writing about science, with a focus on astronomy, for decades. She began her career at Astronomy Magazine and made regular contributions to other outlets, including AstronomyToday and the Sierra Club. She has nine published books, including a children’s picture book, Solar System Forecast, and a young adult dystopian novel, A Different Sky.<\/p>\n<\/p><\/div>\n<\/p><\/div>\n
![\"Earth's](\"https:\/\/earthsky.org\/upl\/2026\/01\/Earth-and-Mars-orbits-NASA-e1768349352842.jpeg\")