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

Roughly four and a half billion years ago the planet Theia slammed into Earth, destroying Theia, melting large fractions of ...

New research shows that Theia, the planet that collided with Earth and formed the Moon, was a rocky world born closer to the ...

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 ...

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 ...

Simulations reveal that Jupiter’s rapid growth disrupted the early solar system, creating rings where new planetesimals ...

A tiny meteorite is rewriting what scientists thought they knew about the origins of our solar system. New evidence found in shavings from a meteorite known as Northwest Africa 12264 — a 50-gram (1.8 ...

Our solar system is a smashing success. A new study suggests that from its earliest period — even before the last of its nebular gas had been consumed — Earth’s solar system and its planets looked ...

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 ...

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 ...