I don’t need to tell you that the Earth’s climate is not constant and it is not just because of the climate change: If we look at it in perspective, throughout the history of the planet it has gone through glaciations and warm periods. Many of these changes find explanation in the Milankovitch cycles or orbital variations, that is, the slow changes in the Earth’s orbit and the inclination of its axis due to the gravitational attraction of other planets.
The surprising influence of Mars. It was known that the giant Jupiter or the nearby Venus are largely to blame, but now we have discovered another secondary actor that has gained importance: Mars, as explained this study collected in Publications of the Astronomical Society of the Pacific and led by scientist Stephen Kane. What’s surprising about it? That Mars only has 10% of the mass of the Earth, hence there are simplified climate models that downplay its importance.
The simulations. The hypothesis is: what would happen to the Earth’s orbit if Mars were much larger or did not exist? Since human research teams do not have millions of years to wait, they used simulations with a solar system model of ten million years each to study gravitational interactions. The only factor they changed in each simulation was the mass of Mars: from zero (Mars does not exist) to being ten times larger than Earth.
Mars “weighs” much more than we think. And the results were conclusive: Mars is directly responsible for the “Great Cycle”, a 2.4 million year gravitational beat in which Mars rhythmically stretches and shrinks the Earth’s orbit, acting as a metronome that regulates the amount of solar radiation received and regulates the frequency of ice ages. Without Mars, that cycle would not exist. However, Kane nuance: “It doesn’t mean that without Mars the Earth wouldn’t have ice ages, but it would completely change the frequency with which they occur.”
But if Mars were giant, Earth’s climate cycles would also change: they would be shorter and more extreme, going from an ice age to suffocating heat waves. In short, life adaptation would become more complicated. What would not change, according to the study, is the “great Jupiter – Venus cycle”, the 405,000-year gravitational pattern driven by a secular resonance of both planets that acts as the “master clock” of the Earth’s climate as it is the most stable and constant cycle in the planet’s geological history.
Why is it important. Knowing better the influence of the planets around us on the climate is good news that helps us better understand our past and be able to glimpse the future with more precision. But it has an impact on the search for habitable exoplanets: it is not enough to find something similar to Earth, but you also have to look at its neighbors and pay attention to the fine print. That is, if it has a “Mars-type” planet nearby but of great mass, its climate has every chance of being too chaotic for life.
In Xataka | Mars has just entered the exclusive club of planets with rays. This is discouraging news for NASA.
In Xataka | We had been wondering for decades how Mars could have water, cold and life. Today we finally have an answer
Cover | Photo of Planet Volumes in Unsplash
GIPHY App Key not set. Please check settings