In a The 92-page paper to be published in Physics Reports, a team of researchers at Caltech, examines the evidence for Planet X's existence and describes a world that is closer and smaller than previously thought.
Almost a decade after the poor Pluto was demoted from The ninth planet is just another of many dwarf planets, an intriguing paper was published by one of the "Pluto-killing" astronomers and his former students. The hypothesis suggested a larger, unseen even further out on the edge of our solar system.
"In essence, three years ago, we knew that the very distant Kuiper belt objects orbits clustered together, "Konstantin Batygin, the junior half of the duo, told me in an email Tuesday. "And we could demonstrate with the help of computer simulations that the only sensible reason for this clustering was the existence of Planet Nine."
The idea is that the distant objects of the Batygin mention are influenced by the gravitational pull of a large planet
Now CalTech's Batygin, his former mentor Michael Brown (aka " PlutoKiller " on social media) and colleagues Fred Brown and Juliette Becker from the University of Michigan have an update for us "Our new efforts, both theoretical and numerical, suggest that in the original paper we over-estimated the parameters of Planet Nine," Batygin explained.
The new analysis paints a picture of a planet with a mass five times more than Earth and which is located about 400 astronomical units (AU) away. For comparison, Pluto is only about 40 AU from us. The authors also conclude that the unseen planet is likely to be a rocky super-Earth rather than a gas giant. But the prospects for habitability are, of course, quite dim, just as the sun would be on such a distance.
"Although this analysis does not say anything directly about whether the Planet Nine is there, it indicates that the hypothesis is based on solid foundation, "said Brown, a professor of planetary astronomy at Caltech, in a release.
The paper also seeks to address some of the criticisms of the Planet Nine hypothesis and alternate explanations for the weirdness observed in the Kuiper Belt. For example, Batygin and colleagues are not convinced by a competing theory that says a massive disk of debris beyond Neptune could explain the weird orbits of distant Kuiper Belt objects as well as unseen super-Earth.
"The most powerful argument in favor of Planet Nine is that the independent lines of evidence can be explained by a proposed new planet with the same properties. In other words, there are several reasons to believe that Planet Nine is real, not just One, "said co-author Fred Adams.
If Planet X does exist and as this latest paper describes it, it will also be a key missing piece to our solar system.
As the exoplanets around the catalog other stars has rapidly expanded over the past decade, it has become increasingly clear that our system is actually quite unusual. That's because rocky super-earths seem to be very common elsewhere, but there is no one in our solar system.
"Planet Nine is going to be the closest thing we will find to a window into the properties of a typical planet of our galaxy, "Batygin explained.
But he concedes that all the speculation around Planet X will remain just that until someone finally spot it.
" The prospect of one day seeing the real images of Planet Nine is absolutely electrifying, "he says. "Although finding the Planet Nine astronomically is a great challenge, I'm very optimistic that we will image it in the next decade."