This hypothetical world, dubbed "Planet Y," could be around the same size as Earth and may exist alongside another popular Planet Nine ... Planet X, likely lurks somewhere within the Kuiper Belt — a ...

Siraj’s Planet Y search started about a year ago when he was trying to find out whether the shape of the Kuiper Belt is flat. “The planets of the solar system have slight tilts up and down, but ...

When you buy through links on our articles, Future and its syndication partners may earn a commission. Planet Nine is a hypothesized massive planet, first proposed in 2014, that is speculated to orbit ...

A recent study by Princeton University astronomers suggests the possible existence of a previously undetected planet in our ...

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 ...

Scientists may have discovered a dwarf planet far beyond Neptune — an unearthing that may disprove a longstanding theory about the possibility of a giant ninth planet. The dwarf planet's existence ...

A team of scientists at the Institute for Advanced Study School of Natural Sciences in Princeton, New Jersey, might have found a new dwarf planet, potentially leading to more evidence of a theoretical ...

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 ...

Exoplanet hunters Christopher Watson and Annelies Mortier explain the long search for a 'twin Earth' capable of sustaining ...

The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have dubbed ...