The search for a ninth planet in our solar system could reach a turning point as soon as this year, according to a planetary scientist involved in the hunt for a mysterious object believed to be lurking in the outer reaches of the Solar System. For the past decade, astronomers around the world have been searching for evidence of another resident in our planetary neighborhood. As far back as 2016, there were already hints that something might be out there, given the odd orbits of distant objects like Sedna, discovered in 2003. Now, two astronomers—California Institute of Technology (Caltech) researchers...