Just like in a game of chess sometimes you have to sacrifice a piece to protect the queen,the early solar system could have kicked out a giant planet to save Earth, according to a new study published in the journalThe Astrophysical Journal Letters.
As explained by David Nesvorny, from the Southwest Research Institute (USA), there is evidence that, when the solar system had just completed600 million years, the orbits of the giant planets were affected by a dynamic instability that caused the giant planets and smaller bodies to drift away from each other. However, this theoretical scenario presents a problem: Jupiter’s orbit changes should have pushed Earth to collide with Mars or Venus, something that obviously did not happen. Astronomers have solved this apparent contradiction with the“jumping Jupiter” theory, which bets because the change of orbit of Jupiter was carried out very quickly, in a kind of “jump”, and that, for that reason, it did not cause instabilities in the regions near the Sun.
To see if the Jupiter theory is true, Nesvorny has carried out thousands of computer simulations. And he has found that there is something that does not add up either, since the jump of Jupiter should have thrown Uranus or Neptune out of the solar system. Trying to find a solution, Nesvorny repeated the simulation includingfive giant planets instead of the current four. And from that moment everything began to make sense. According to his new model, when Jupiter jumpedlaunched a giant planet similar to Neptune out of the solar system, while the four rocky planets (Mercury, Venus, Earth and Mars) kept spinning “quietly” closer to the Sun.
“The possibility that the solar system had more planets and expelled some is conceivable in light of recent findings on a large number offree and lonely floating planets in interstellar space“, Nesvorny concludes in his article.
