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 ...

From the cratered companion that lights Earth's night sky to the hundreds of icy worlds circling the Solar System's giant ...

The outer solar system once seemed like a quiet backwater. But a glut of tiny, strange moons with unruly orbits are coming into view, revealing hints of a surprising past – and the origin of Saturn's ...

While life on Mars (and Venus) has long been an obsession for those wondering if we're alone, there are other places in our ...

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 ...

At a young age, we're told how the sun warms Earth and makes life possible. That idea sticks with most of us for life. But when we want to understand things more thoroughly and we dig more deeply, we ...

The outer planets of the solar system are swarmed by ice-wrapped moons. Some of these, such as Saturn's moon Enceladus, are known to have oceans of liquid water between the ice shell and the rocky ...

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 ...

Several small worlds beyond Jupiter are not just frozen rubble. Beneath their shining skins, many hide oceans of liquid water. New research says those seas do not always stay calm. When the ice lids ...

Astronomers recently detected a stray quasi-moon in our planet’s orbit, but it's hardly the first stowaway to hang out around Earth. Unlike the Earth's moon, quasi-moons are not gravitationally bound ...