Astronomers have predicted how big this hypothetical world could be, how far away it could lie and even where it should be in ...

"As a consequence," Brown says, "if Planet Nine exists, there should be a pretty smooth population of objects that have a perihelion distance from just outside Neptune's orbit to all the way in to ...

Known as Planet Nine or Planet X, it is a hypothetical planet ... the BBC as a "doughnut shaped region of icy bodies" beyond the orbit of Neptune – that had unusually warped orbits around ...

The idea regarding the possible existence of a ninth planet, called Planet Nine/Planet X, in the solar system started with Caltech professors Mike Brown and Konstantin Batygin looking far out ...

Planet Nine, a massive icy world ... Space Deathtrap': The terrifying way climate change could destroy low Earth orbit for good ...

Considered a solitary star for its lack of stellar companions, Barnard's Star is notoriously lonely—signs of any exoplanets ...

Nine in 10 useful satellites are located in an area called low Earth orbit — as is most of the junk. Objects in this zone move at about 17,000 miles per hour, making it hard to avoid collision.

In fact, previous studies have claimed that even a tiny shift in Jupiter’s orbit could have bizarre effects on Earth. But what if we put an entire planet between Jupiter and Mars? According to ...

NASA's SPHEREx observatory is now in space for a two year year mission to create a 3D map of the entire celestial sky.