Our solar system may have a ninth planet after all, following the declassification of Pluto nearly two decades ago, ...

A new study, however, identifies a possible candidate. A separate team of astronomers compared 1983 data from the Infrared ...

If the object really is Planet Nine, it would be larger than Neptune and exist 700 times further from the sun than Earth.

The solar system is our cosmic neighborhood ... Neptune and then the possible Planet Nine. It's a dynamic system shaped by gravity and time, and while we've learned a lot, it still holds plenty ...

A 9th planet in our solar system might be found — and no, it’s not Pluto - Is there another planet out there? Researchers say they have hints of a new candidate ...

This week, an old astronomical controversy is renewed as researchers present new evidence for a hidden "Planet X" in our ...

For years, astronomers have toyed with the idea that the Sun hides an extra planet so distant and dim that even the best ...

A new look through decades-old data has unveiled some of the most compelling evidence yet of a hidden ninth planet in the far reaches of our solar system, far beyond ...

The long-theorized Planet 9, which astronomers have speculated could be a Neptune-sized planet that has been lurking on the outer edge of the solar system, could explain the unusual clustering and ...

A ninth planet the size of Neptune may be hidden in the far reaches of the solar system, but the evidence has left some experts skeptical.

For nearly a decade, scientists have been on the hunt for Planet Nine – a hypothetical celestial object on the edge of our Solar System. Now, astronomers claim to have discovered this ninth ...

"How planets are born is an unsolved area of research," astrophysicist Daniel Price of Australia's Monash University told ...