Astronomers are closing in on one of the most tantalizing possibilities in planetary science, evidence that a previously ...

On January 5, 2005, astronomers at NASA discovered Eris, the second-largest dwarf planet in the solar system. Eris is just ...

LONDON — 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 ...

Kuiper Belt clues, competing ideas, and how Rubin Observatory could finally reveal the hidden world soon by 2026.

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 ...

The newly identified cluster of Kuiper Belt objects lies about 4 billion miles from the Sun, offering fresh clues about how ...

Far beyond Neptune, something heavy appears to be tugging on the outer solar system, bending the paths of distant icy worlds ...

Astronomers may have uncovered a massive hidden planet far beyond Neptune, using decades-old infrared data. The object’s ...

It is a question that feels like it should have a straightforward answer: how many planets are there in our solar system? Since Pluto was relegated back down to dwarf planet status, almost everyone ...

The giant planets weren't always where we find them today. Jupiter, Saturn, Uranus and Neptune formed in a more compact configuration and later underwent a violent reshuffling that scattered them to ...

The European Southern Observatory said the discovery as "the first clear detection of a baby planet in a disc with multiple rings" Abigail Adams is a Human Interest Writer and Reporter for PEOPLE. She ...