NEW SCIENTIST - Compared with Earth, Mars is tiny, yet it seems to have an outsized effect on our planet’s climate cycles. Similar small planets could affect the climates of worlds beyond our solar system, which we must begin to take into account when evaluating their potential habitability.
Stephen Kane at the University of California, Riverside, and his colleagues found this effect by running simulations of the influence Mars would have on Earth’s orbit if it were a different mass, from 100 times its actual mass to if it were gone entirely. “I came to this from a perspective of scepticism, actually, because I had trouble believing that Mars, which is only a tenth the mass of Earth, could have such a profound effect on Earth’s cycles, so that’s what motivated this study to turn that knob of Mars’s mass and see what happens,” says Kane.