There have been questions about a mysterious ninth planet in our solar system for nearly a decade. Pluto was unseated as number nine in 2006. Now, a group of international researchers say they may ...

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 ...

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 ...

For the first time in years, astronomers are seriously talking about adding a new member to the solar system’s planetary ...

(CNN) — 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 ...

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. Labelled as planet X, prominent astronomers ...

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 ...

Astronomers have discovered a new tiny planet in the Kuiper belt, which has an unusual very elongated orbit. The new object has already been named 2017 OF201. The planet orbits the Sun about once ...

This discovery was made by two of NASA’s most celebrated telescopes. This illustration provided by Dan Durda shows the exoplanet Kepler-1625b with a hypothesized moon. On Thursday, Oct. 4, 2018, two ...