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Computer runs allowed the experts to switch planets on and off, turning the solar system into a controlled test. The simulations were built at the University of California, Riverside (UC Riverside<\/a>).<\/p>\n Stephen R. Kane, Ph.D., a professor of planetary astrophysics, started out doubtful and checked his own assumptions while modeling how planets tug each other.<\/p>\n \u201cI knew Mars had some effect on Earth, but I assumed it was tiny,\u201d said Kane.<\/p>\n Tracing the orbital rhythms<\/p>\n Long-term climate swings begin with slow changes in Earth\u2019s path and spin that adjust where sunlight falls.<\/p>\n Scientists call these Milankovitch cycles<\/a>, orbit-driven patterns in solar heating, and they match signals found in ocean sediments.\u00a0<\/p>\n The simulations tracked the eccentricity<\/a>, how stretched an orbit becomes, and the tilt that sets where summer sunlight concentrates.<\/p>\n Small changes in those parameters can alter summer melting, so ice sheets can expand when cooler summers let snow persist.<\/p>\n What vanished without Mars<\/p>\n To isolate Mars\u2019 role, the team at UC Riverside reran their solar system model after deleting the red planet from the lineup.<\/p>\n A 430,000-year rhythm linked to Venus and Jupiter stayed, but a 100,000-year cycle disappeared in the no-Mars run.<\/p>\n \u201cWhen you remove Mars, those cycles vanish,\u201d said Kane after comparing the frequency patterns across each simulation run.<\/p>\n That difference pins the missing cycles on Mars, helping researchers connect orbital math to patterns preserved in rocks.<\/p>\n The weight of a small planet<\/p>\n Mars is about half Earth\u2019s size and only about one-tenth of Earth\u2019s mass<\/a>, yet its orbit sits far enough out to matter.<\/p>\n In the model, boosting Mars made certain orbital frequencies speed up because a heavier planet tugs harder each pass.<\/p>\n \u201cAnd if you increase the mass of Mars, they get shorter and shorter because Mars is having a bigger effect,\u201d said Kane.<\/p>\n Even small differences in a planet\u2019s mass could reshape long-term climate rhythms on nearby worlds, depending on orbital layout.<\/p>\n Earth\u2019s tilt and its neighbors<\/p>\n Earth\u2019s tilt changes slowly, and the Moon<\/a> keeps those swings from becoming chaotic over long spans.<\/p>\n Scientists describe the tilt as obliquity<\/a> \u2013 the angle between spin axis and orbit plane \u2013 and it shapes seasons.<\/p>\n Today the axis sits near 23.5 degrees, and the simulations tracked how that angle would drift under different Mars masses.<\/p>\n \u201cAs the mass of Mars was increased in our simulations, the rate of change in Earth\u2019s tilt goes down,\u201d said Kane.<\/p>\n From sunlight to ice<\/p>\n Orbital changes matter because ice grows when winter snow survives summer, and that balance depends on seasonal sunlight.<\/p>\n Higher eccentricity increases the contrast between Earth\u2019s closest and farthest solar distances, changing the strength of seasonal heating.<\/p>\n Tilt adds another lever, since a slightly different angle can move summer heat toward or away from high latitudes.<\/p>\n These drivers can pace glacial advances, but greenhouse gases and ocean circulation still decide how big the temperature swings become.<\/p>\n Sediments record slow forcing<\/p>\n Layered mud on the seafloor builds up slowly, and its chemistry and grain size can follow repeating climate patterns.<\/p>\n Researchers match those layers to calculated orbital cycles, because changes in sunlight can alter winds, rainfall, and ocean mixing.<\/p>\n Mars-linked periods in the new simulations help explain why some sediment records show strong beats beyond the familiar short cycles.<\/p>\n Better links between orbital physics and rock layers could sharpen geologic dating, while also revealing when Earth\u2019s orbit behaved differently.<\/p>\n Hints for other worlds<\/p>\n Outside our solar system, astronomers often find rocky planets near their stars, with additional worlds farther out.<\/p>\n Astronomers use the term habitable zone<\/a> to describe the region where surface water can stay liquid, yet neighboring planets can still push climates around.<\/p>\n \u201cWhen 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,\u201d said Kane.<\/p>\n For now, most exoplanet data cannot reveal million-year cycles, so the idea guides target selection more than prediction.<\/p>\n What simulations can\u2019t show<\/p>\n The models isolate gravity in a controlled setting, but real Earth includes feedbacks that can mute signals.<\/p>\n Ice sheets respond to temperature, but temperature also depends on carbon dioxide, volcanic aerosols, and ocean currents over long spans.<\/p>\n The simulations also begin with today\u2019s planetary layout, so they cannot recreate past rearrangements or earlier solar system instabilities.<\/p>\n Still, the exercise pins down which orbital cycles come from which neighbors, a key step before full climate modeling.<\/p>\n A small planet matters<\/p>\n Taken together, the results show that Mars helps tune Earth\u2019s orbital geometry, setting the timing of slow climate cycles.<\/p>\n Future work can tie these orbital inputs to ice-sheet models and test whether other solar systems share similar sensitivities.<\/p>\n The study is published in Publications of the Astronomical Society of the Pacific<\/a>.<\/p>\n \u2014\u2013<\/p>\n Like what you read? Subscribe to our newsletter<\/a> for engaging articles, exclusive content, and the latest updates.<\/p>\n Check us out on EarthSnap<\/a>, a free app brought to you by Eric Ralls<\/a> and Earth.com.<\/p>\n \u2014\u2013<\/p>\n","protected":false},"excerpt":{"rendered":"New simulations suggest Mars helps set a 2.4 million-year rhythm in Earth\u2019s orbit that can steer the timing…\n","protected":false},"author":2,"featured_media":325013,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[111,139,69,147,392],"class_list":{"0":"post-325012","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-space","8":"tag-new-zealand","9":"tag-newzealand","10":"tag-nz","11":"tag-science","12":"tag-space"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/325012","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/comments?post=325012"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/325012\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/325013"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=325012"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=325012"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=325012"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}