We’re closer than ever before to knowing whether there is a ninth planet whooshing around the sun – and, alas, it’s not Pluto. Planet X, also called Planet Nine, is a hypothetical planetary body seven ...

It's an evocative idea that has long bedeviled scientists: a huge and mysterious planet is lurking in the darkness at the edge of our solar system, evading all our efforts to spot it. Some astronomers ...

There has been a lot of back and forth about the existence of a mysterious ninth planet, often referred to as "Planet Nine" or even "Planet X." Now, though, researchers say there is likely at least a ...

An artist's illustration of a possible ninth planet in our solar system, hovering at the edge of our solar system. Neptune's orbit is shown as a bright ring around the Sun. Scientists in Taiwan ...

Astronomers believe they have uncovered evidence of a previously unknown ninth planet lurking in the not-too-distant reaches of the solar system. This hypothetical world, dubbed "Planet Y," could be ...

Alfredo has a PhD in Astrophysics and a Master's in Quantum Fields and Fundamental Forces from Imperial College London.View full profile Alfredo has a PhD in Astrophysics and a Master's in Quantum ...

A possible cousin of Pluto seems to be circling the far reaches of the solar system. The dwarf planet candidate 2017 OF201 travels in a superwide orbit, with the sun relatively near one end of its ...

A new study has proposed the existence of Planet Y, an alternative Planet Nine candidate that is smaller and closer to Earth than the hypothetical Planet X, which astronomers have been hunting for ...