Is a massive planet lurking beyond Pluto? Tyche planet mystery: In 1999, scientists proposed a world four times Jupiter's mass; 25 years later, the debate continues

Is there a giant hidden planet beyond Pluto? Tyche planet mystery explained: In 1999, astronomers proposed Tyche. They suspected a giant world hiding deep in the Oort Cloud. It was four times bigger than Jupiter. Weird comet paths pointed right to it. Then in 2014, NASAs WISE telescope scanned the sky and found zero evidence. Tyche was officially ruled out. Still, the search for a hidden outer planet isn't over.