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 ...

Is there a massive undiscovered planet on the outer reaches of the solar system? The idea has been around since before the discovery of Pluto in the 1930s. Labeled as planet X, prominent astronomers ...

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 ...

WASHINGTON (Reuters) -Scientists have identified an object about 435 miles (700 km) wide inhabiting the frigid outer reaches of our solar system that might qualify as a dwarf planet, spotting it as it ...

For over a century, astronomers have wondered if there’s an extra planet in our Solar System that we haven’t been able to detect yet. It seems like we get another “Planet Nine” candidate — formerly ...

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 ...

Earth has a newly-discovered neighbor in the solar system. But the heavenly body – possibly a dwarf planet à la Pluto – isn't a frequent visitor. Located beyond Neptune, its extreme orbit ...

It’s possible the trans-Neptunian object, dubbed 2017 OF201, is large enough to qualify as a dwarf planet, making it an “extreme ‘cousin’ of Pluto,” according to Institute for Advanced Study postdoc ...

Is there a massive undiscovered planet on the outer reaches of the solar system? The idea has been around since before the discovery of Pluto in the 1930s. Labeled as planet X, prominent astronomers ...

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 ...