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 ...

Most of us learned the basics of our solar system in school. Eight planets, one sun, some moons, a couple of asteroid belts.

Far from the Sun’s heat, orbiting the outer planets of the solar system, are moons with oceans of liquid water beneath their frozen surfaces. Keith Cooper finds out how planetary scientists are ...

Moons may seem like quiet companions to the planets, but many of them are worlds every bit as fascinating as the planets themselves. Some are covered in oceans, some erupt with lava, and others hide ...

What is the difference between a moon and a planet? Trick question! According to scientific definitions, there often isn’t much of a difference at all. That might seem counterintuitive, but it’s true.

This year, astronomers discovered more than 100 previously unknown moons in our own solar system. There may be many more yet to be discovered, and cataloguing them could help us better understand how ...