Findings of a study published recently in The Astrophysical Journal are indicating that Jupiter ejected a giant planet from the solar system around 4 billion years back.
For those who don’t know: it is believed that major planets get ejected from solar systems when gravitational field of a giant planet (for instance, Jupiter, Saturn, etc.) attracts another massive body and the resulting acceleration between the planets gives birth to a close encounter, which eventually breaks any one body free of the shared gravitational pull.
This notion got rejected by a team of Canadian astronomers based on the history of planet ejections. Gas giants responsible for ejecting each other result in massive encounters in the atmosphere surrounding them. This in turn extinguishes the minor bodies present in the orbits around them.
As anything of this sort didn’t happen in Saturn’s atmosphere, astronomers started believing that the planet’s moons and their orbits might be the reason behind the ejection. The research team studied the scenario to gather evidence supporting the above-mentioned notion.
Ryan Cloutier, a scientist representing the University of Toronto and a member of the research team carrying the study, said that a similar study conducted for Saturn’s moon Iapetus showed that it would have been much tougher for the ringed planet to eject an ice giant and then merge the orbit of Iapetus with that of a Kronian satellite. According to him, the likelihood of such a situation being true is only about 1%. He added that uncertainties about Iapetus’ formation on an unusual orbit make the interpretation of this finding complicated.
In 2011, astronomers used to believe that Saturn was the actual culprit. However, at this moment they have been forced to believe something different. Studies conducted over the years have made it clear that such a scenario would have had a strong impact on the surrounding orbits of the planet.
Cloutier said that he and his team have quantitatively calculated that the possibility of reconciliation between a current orbit of Callisto (a moon of Jupiter) and that of a regular Jovian satellite following the ejection of an ice giant by the solar system’s biggest planet Jupiter is 42%. Based on this calculation, the researchers have concluded that the hypothesis of the existence of a 5th giant planet is true.