On January 20, 2016, a team of astronomers from the California Institute of Technology (Caltech) announced in the Astronomical Journal that they had found evidence of the existence of a huge unknown object in the Solar System. This would be located about twenty times farther than Neptune and, according to the computer simulations developed by these experts, its presence – it would be ten times more massive than the Earth and would have a radius between two and four times greater – would explain the strange dance. orbital that some dwarf planets of the Kuiper belt follow. It was immediately christened Planet Nine.
Although these scientists are reasonably sure of its existence – they believe there is a 90% chance that it is so – it is not easy to find it, much less observe it directly with telescopes. Planet Nine would be so far away that it would barely reflect light . In fact, it would take about 15,000 years to go around the Sun and at its closest approach to our planet it would be two hundred times farther than the distance that separates the Sun from the Earth.
Since the Caltech researchers published their essay, several groups of experts have tried to provide more information about their position and origin . Some have suggested that Planet Nine could be a gas giants that would have been ejected from its original orbit, closer to the Sun, a few hundred million years after the formation of our system. Now other astronomers, coordinated by physicist Alexander Mustill of Lund University in Sweden, point out that Planet Nine could actually be an extrasolar world.
The star king would have seized him about 4,500 million years ago , in the early stages of his life, after approaching another sun. According to these scientists, these types of encounters are not strange, since stars are formed in clusters and when they are young they sometimes pass very close to each other. The new computer model they have built shows that Planet Nine would be part of that neighboring star’s system . Probably by then he would follow an eccentric orbit that would take him far from it. So much so that it could not have eluded the gravitational pull of the Sun when the two systems approached. In this way, it would have become part of ours.
“It is ironic. Astronomers manage to find exoplanets hundreds of millions of light years away, and there is probably one that has gone unnoticed in our own backyard, ”says Mustill.
Image: Tomruen / Nagualdesign via Wikimedia / CC
