Scientists may have discovered a dwarf planet far beyond Neptune — an unearthing that may disprove a longstanding theory ...

Artist's impression of Planet Nine – a suspected “wide-orbit” planet – with the Sun in the distance; Neptune's orbit is shown ...

Our solar system used to have nine planets. Astronomer Mike Brown, also known as “the man who killed Pluto,” said he got hate mail from kids and obscene calls at 3 a.m. for years after his ...

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 ...

Pluto was reclassified as a dwarf planet in 2006. Our solar system may have a ninth planet after all, researchers say. The possibility that an additional planet may be hidden far into the solar ...

A stunning photo taken in Somerset has showed every single planet in the solar system at the same time during a rare alignment that won't happen again until 2040.

Mike Brown is convinced that beyond Neptune, at the far reaches of our solar system, there's an unseen giant planet. "This is the 5th largest planet in our solar system, lurking out there, waiting ...

The chance of a planet forming in the outer reaches of the solar system – a hypothetical Planet Nine – could be as high as 40 per cent, but it would have been a rough start. Close.

Centimeter-sized pebbles have been detected in protoplanetary discs using e‑MERLIN, filling in a critical phase of planet ...

A fascinating glimpse into how a solar system like our own is born has been revealed with the detection of planet-forming ...

If there were one, that Planet Nine would "nudge the closest part of 2017 OF201's trajectory inward until Neptune flung it out of the solar system." Because 2017 OF201 is there, that could be an ...