In the early years of the solar system, the giant planets that were still forming, the gas giants like Jupiter, Saturn, Uranus, and Neptune, had a weird back-and-forth pushing one of their companions out of the Sun’s gravitational grasp . it was put in place and the orbits of the planets stabilized. Our planetary system was already in its final configuration.
But what triggered this early planetary movement?
A team of scientists has developed a series of computer simulations that suggest that fiery radiation from our then young sun led to the alteration of the orbits of the giant planets. As a result, the four largest planets in our solar system might not have taken their final places until within 10 million years of the solar system’s birth about 4.6 billion years ago. That’s considerably faster than the 500 million years that earlier research had suggested.
‘planetary shuffle’
This finding revealed by computer simulations is highly innovative . While there was plenty of evidence indicating something akin to ‘planetary shuffling’ in our solar system’s early history, something that scrambled the orbits of the giant planets, it’s the first time such a simulation has been shown.
What would have triggered this instability of the giant planets of the solar system? To identify it, scientists ran computer simulations of the thousands of ways the early solar system could have developed.
To play with the parameters, they modified those of the disk, its mass, density and how fast it would have evolved. The simulations also included the giant planets in formation, five of them, in fact; this is because astronomers believe that a third ice giant, in addition to Uranus and Neptune, was once part of our solar system but was eventually ejected.
When the Sun began to burn hydrogen in its core approximately 4.6 billion years ago (and thus officially become our star), its ultraviolet emission would have hit the gas in the disk, ionizing it and heating it to tens of thousands of degrees. .
In the simulations, as the inner part of the disk dissolved, planets that were still forming felt less gravity in that region, but the same amount of pull from the outer region of the disk. This gravitational twist, as experts call it, could have triggered a rebound effect.
Thus, the researchers found that as solar radiation evaporated the disk, a planetary reorganization almost always occurred in the simulations.
Referencia: B. Liu, S.N. Raymond and S.A. Jacobson. Early solar system instability triggered by dispersal of the gaseous disk. Nature. Vol. 604, April 28, 2022, p. 643. doi: 10.1038/s41586-022-04535-1.
