On Earth, you can look up at night and see the Moon shining bright from hundreds of thousands of miles away. But if you went to Venus, that wouldn't be the case. Not every planet has a moon — so why ...

So far, humanity has yet to find its first "exomoon"—a moon orbiting a planet outside of the solar system. But that hasn't been for lack of trying. According to a new paper by Thomas Winterhalder of ...

The planet Uranus and its five biggest moons may not be the dead sterile worlds that scientists have long thought. Instead, they may have oceans, and the moons may even be capable of supporting life, ...