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Astronomers have found new evidence of an icy planet at the far edge of our solar system, and they’re calling it “Planet Nine.” Authors Michael Brown and Konstantin Batygin describe the planet as five to 10 times bigger than Earth. Dwarf planets and other small objects reportedly have orbits that are influenced by the gravity of Planet Nine, which they call a “massive perturber.” The pair of researchers initially set out to prove that Planet Nine didn’t exist, but were surprised by their own findings. Brown was instrumental in stripping Pluto of its planetary designation in 2006.