Our solar system now, once again, officially consists of only eight planets. Although largely debunked, speculation continued ...

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 ...

Planet Y is the latest in a series of hypothetical solar system planets that scientists have proposed in recent years, all with slightly different characteristics, but collectively believed to be ...

When you buy through links on our articles, Future and its syndication partners may earn a commission. Astronomers have been actively hunting for a ninth planet in the solar system for almost a decade ...

Astronomers are gathering evidence of a massive hidden planet lurking beyond Neptune. Trump Cuts Millions After California ...

A newly discovered warp in the outer Solar System may have been created by a small, rocky world, much closer to the Sun than ...

Might the solar system harbor not just one, but two unknown planets? A fresh study of the Kuiper Belt’s structure has revived ...

Astronomers are investigating a potential hidden planet, dubbed Planet Y, far beyond Neptune. Its gravitational pull is suspected to be causing unusua ...

A distant gas giant the size of 10 Jupiters is now the first planet outside Earth's solar system to be mapped in three ...