We know it as the “lunar tilt problem” and astronomers have long tried to explain this angle of 5º that the lunar orbit presents with respect to the Earth’s orbital plane (10 times more than expected) and that it is one of the reasons why we see lunar eclipses every six months instead of one every month. The possible resolution to the mystery appears in the journal Nature .
It all starts with the formation of the Moon. One of the theories that has had the most acceptance among the scientific community is based on the fact that our satellite was formed as a result of the fragments ejected after the collision of a monstrous object with the primitive Earth. But, if that had happened, the Moon would not have changed its orbit afterwards. What happened then?
A team of researchers from the Observatory of the Côte d’Azur (France), Kaveh Pahlevan and Alessandro Morbidelli, have carried out various computer simulations to understand the physical limits of this event. “The lunar orbit that we currently observe can be reproduced from the interaction with a small amount of mass (approximately 0.0075 to 0.015 Earth masses, which could end up being incorporated into the Earth) transported by a few bodies, according to the limitations and what the models say ”, explain the authors.
Their simulations have revealed that the lunar orbit was tilted, probably a few tens of millions of years after its formation, due to gravitational interactions with small planetary bodies, which were found in the early inner solar system; that is, the gravitational action of these planetesimal objects caused a certain inclination – due to the cumulative effect of these interactions – of the Moon .
“Previous models of the origin of the Moon’s inclination are based on complex processes that involve periodic gravitational resonance with the Sun or the Moon with its precursor disk, in both cases with enough limitations to be successful; but the new mechanism is much simpler ”, explains astrophysicist Robin Canup, from the Southwest Research Institute (Boulder, USA), in another article published in Nature.
