A telescope has discovered a new world on the edge of the Milky Way – potentially confirming the ‘Planet X’ theory. Beyond Neptune, a smaller ‘ninth’ planet has been identified in the Kuiper Belt. If ...

In 1906, astronomer and businessman Percival Lowell launched a search for "Planet X," a hypothetical giant planet orbiting the sun beyond Neptune. Lowell was convinced that Planet X existed based on ...

Astronomers used a telescope in Hawaii to find a new object on the outer edges of our solar system, helping to fuel evidence of a long-standing theory about Planet Nine, or Planet X. For years, ...

Astronomers have been searching for evidence that Planet Nine exists for years Becca Longmire is a digital news writer-reporter at PEOPLE. She has been working at PEOPLE since 2024. Her work has ...

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 ...

On a chilly morning in February 1930, a young astronomer named Clyde Tombaugh was hunched over a blinking comparator at the ...

Humanity has discovered thousands of planets around other stars in the galaxy — so why aren’t we sure how many are in our own backyard? The existence of a distant, as-yet-undetected planet in our own ...

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 ...

In large part, it is impossible to have escaped notice of a rather large debate swirling in the planetary community around a theorized super-Earth planet in the outer reaches of our solar system, the ...

The cold and mysterious Oort cloud at the edge of our solar system may be hiding a rogue exoplanet, new research suggests. When you purchase through links on our site, we may earn an affiliate ...