The red planet has made Earth’s climate what it is today. Mars’ gravitational pull serves as a stabilizing force for our home’s orbit, tilt and position from the sun. Without it, life could potentially have been a lot different from what we know today.
How does Mars’ gravity impact Earth? Despite being approximately half the size of Earth and one-tenth its mass, Mars’ gravity has had a sizable effect on Earth’s climate, according to a study published in the journal Publications of the Astronomical Society of the Pacific. The planet is “quietly tugging on Earth’s orbit and shaping the cycles that drive long-term climate patterns here,” said the study’s release.
Earth’s climate is largely driven by Milankovitch cycles, “long-term variations in our planet’s orbit and tilt governed by the gravitational pull of other planets in the solar system,” said Space.com (a sister site of The Week). One cycle takes approximately 430,000 years and is largely affected by Venus and Jupiter. Mars has little to no effect on this cycle, originally leading scientists to believe that the planet did not have much pull on Earth’s climate.
However, it turns out that Mars “punches above its weight,” said Stephen Kane, the study leader and a professor of astrophysics at UC Riverside, in the release. Mars significantly affects two other climate cycles, and “when you remove Mars, those cycles vanish.” If you “increase the mass of Mars, they get shorter and shorter because Mars is having a bigger effect.”
These cycles “affect how circular or stretched Earth’s orbit is (its eccentricity), the timing of Earth’s closest approach to the Sun, and the tilt of its rotational axis (its obliquity),” said the release. This determines “how much sunlight different parts of the Earth receive, which in turn affects glacial cycles and long-term climate patterns,” including ice ages.
What are the implications? Ice ages “changed Earth’s landscapes,” said Tech Explorist. They “shrank forests, spread grasslands and triggered major evolutionary changes, such as walking on two legs, making tools and working together.” So it begs the question, said Kane: “What would humans and other animals even look like if Mars weren’t there?” |