A new dwarf planet, discovered beyond Neptune and described as Pluto's 'cousin,' could void the hypothesis of a Planet X in ...

Sihao Cheng, an astrophysicist at the Institute for Advanced Study’s School of Natural Sciences, led the team that discovered the object, which he described as an "extreme 'cousin' of Pluto," in ...

The newly discovered object, named 2017 OF201, has a 25,000-year orbit and is believed to be a large contender for dwarf ...

"Meanwhile, its perihelion—the closest point on its orbit to the sun—is 44.5 times that of Earth's orbit, similar to Pluto's orbit." This extreme orbit, which takes the object approximately ...