The solar system, long believed to be a relatively stable and isolated system of planets, moons, and distant bodies, may have experienced a dramatic shift caused by an unexpected interstellar ...

Jupiter is our solar system's biggest planet by far. It used to be twice as large: Study A recent study found that Jupiter was once twice the size that it is now, making it big enough to swallow ...

An accidental discovery in an astronomy show offers researchers a new clue about the mysterious Oort Cloud, a large expanse of icy bodies revolving around the sun.

Captured just days after its discovery, the images offer the clearest view yet of this rare visitor from beyond our solar system.

The Oort Cloud, an expanse of icy bodies in the far reaches of our solar system, is shown here in a scene from "Encounters in the Milky Way," a show at New York City's Hayden Planetarium that spawned ...

Test your knowledge on our solar system, from the biggest and smallest planets to the behemoth mountain on Mars.

Scientists may have found evidence of a ninth planet hiding out beyond Pluto, but is it actually Planet Nine?

Our solar system may have a ninth planet after all, following the declassification of Pluto nearly two decades ago, researchers say.

The finding, published last week in The Astrophysical Journal, will help scientists more accurately understand stars and planets beyond our solar system formed and evolved across billions of years.

Astronomers have discovered that the Solar System traversed the Orion star-forming complex, a component of the Radcliffe Wave galactic structure, approximately 14 million years ago. This journey ...