The Solar System does not have a clear border. The influence of the Sun in certain domains is small enough for the Voyager probes to have escaped into interstellar space, but there are comets and ...

Add Yahoo as a preferred source to see more of our stories on Google. Digital art of distant planet - Dottedhippo/Getty Images On August 24, 2006, our solar system lost a planet. It wasn't by ...

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. Labelled as planet X, prominent astronomers ...

Six planets will be parading through the sky at the end of the month, and you won’t have to stay up late into the night to ...