Every 2.4 million years, Mars tugs on Earth so hard that it reshapes the ocean floor. New geological research suggests that Mars’ gravity pulls Earth closer to the sun in cycles lasting millions of years, warming our climate.
Mars’ gravitational pull on Earth may influence our planet’s climate, new research suggests.
Geological evidence dating back more than 65 million years and taken from hundreds of sites around the world shows that deep-sea currents have repeatedly gone through periods of being stronger and weaker. This happens every 2.4 million years and is known as an “astronomical grand cycle.”
Stronger currents, known as “giant eddies” or vortices, can reach the seafloor in the deepest parts of the ocean, known as the abyss. These powerful currents then wash away large chunks of sediment that accumulate during calmer periods of the cycle, according to a study published March 12, 2024, in the journal Nature Communications.
The study found that these cycles coincide with the periods of known gravitational interactions between Earth and Mars as the two planets orbit the Sun.
“The gravitational fields of the planets in the solar system interfere with each other, and this interaction, called resonance, changes the planets’ eccentricity – a measure of how close to circular their orbits are,” study co-author Dietmar Müller, a professor of geophysics at the University of Sydney, said in a statement.
Because of this resonance, the Earth is pulled slightly closer to the Sun by Mars’ gravitational pull, causing our planet to be exposed to more solar radiation and therefore have a warmer climate, before falling back again – all within 2.4 million years.
The authors of the new study used satellite data to map the accumulation of sediment on the ocean floor over tens of millions of years. They found that there were gaps in the geological record when sediment stopped accumulating within these astronomical cycles. They believe this may be due to stronger ocean currents as a result of warmer weather caused by Mars’ gravitational influence on Earth.
The results support the idea that the Red Planet influences Earth’s climate, just as passing stars and other astronomical objects are theorized to do. However, the observed warming effect is not due to global warming caused by human greenhouse gas emissions, the authors emphasize in their statement.
However, while it is only speculative at this stage, the findings suggest that this cycle could periodically sustain some deep ocean currents if global warming causes them to decrease, the authors say.
“We know that there are at least two separate mechanisms that contribute to the intensity of deep mixing in the oceans,” Mueller said. One of these mechanisms is known as the Atlantic Meridional Overturning Circulation (AMOC), Mueller said. It acts as an ocean “conveyor belt,” transporting warm water from the tropics to the Northern Hemisphere, pulling heat into the deep ocean in the process.
Some scientists predict that the AMOC could collapse within the next few decades, so it’s possible that the ventilation caused by deep-sea gyres could prove beneficial.
“Our deep-sea data, spanning 65 million years, suggest that warmer oceans have more vigorous deep circulation,” Adriana Dutkiewicz, lead author of the study and a sedimentologist at the University of Sydney, said in a statement. “This would potentially keep the ocean from becoming stagnant even if the Atlantic Meridional Overturning Circulation slows or stops entirely.”
