Moons are either gravitationally captured if they are within what's called a planet's Hill sphere radius, or they’re formed along with a solar system. The Hill sphere radius ...

Ultimately, the question of why some planets have moons is still widely debated, but factors such as a planet’s size, gravitational pull, Hill sphere radius and how its solar system formed may ...

From quasi-moons to asteroids with rings, the Solar System is beaming with weird and exotic objects that tell the story of how it came to be billions of years ago.

The ringed gas giant Saturn has officially replaced Jupiter as the planet in our solar system with the most moons. The International Astronomical Union officially recognized 128 new moons orbiting ...

The rest of the moons in our solar system, including Jupiter’s and Saturn’s outer moons, were probably gravitationally captured by their planets. Earth’s Moon is special because it likely ...

Astronomers have captured silicate clouds and a mysterious disk around two giant young exoplanets, revealing surprises that ...

Today, of course, ice is found on almost every planet, even on Mercury. But back then, only the young protoplanets beyond the ice line were cold enough to have it.