The Solar System may look orderly from a distance. Eight planets orbiting one star, ...

A distant 'exomoon' the size of Jupiter is changing how we think about the cosmos.

We used to think moons were the boring sidekicks of the solar system. For decades, we treated them like cosmic leftovers — cold, dead rocks that did nothing but tag along with their parent planets. We ...

A Jupiter-mass object orbiting a brown dwarf could become the first confirmed moon beyond our Solar System.

Moons are natural satellites that rotate around planets or asteroids. They come in many shapes, sizes and types. Larger moons are spherical, but others can have an irregular shape or texture. Although ...

Our moon is closer in size to Earth than any other moon in the solar system is to its associated planet, however it is far from the largest moon around.

Ganymede, Jupiter's largest moon, possesses planet-like dimensions and a hidden ocean. This moon is larger than Mercury and ...

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. Flybys of Jupiter ...

We have an idea of what the solar system's past was like: It was violent and chaotic. However, we are still studying how violent it was. Current models suggest that at some point after their formation ...

Astronomers have found what looks like the first moon outside our solar system, though the team is cautious about calling it ...