Do any of our solar systems' moons have moons of their own?

The Moon has its own Hill sphere with a radius of 60,000 km (about one sixth of the distance between the Earth and Moon) where a sub-satellite ... read more

Either way, moons in our solar system wouldn't have moons for very long. It is (theoretically) possible. After all, you could think of Earth as one of the Sun's moons, and our Moon as a "moon orbiting a moon". That's probably not what you wanted to hear, though. read more

Well actually, one does. Right now, NASA’s Lunar Reconnaissance Orbiter is happily orbiting around the Moon, photographing the place in high resolution. read more

The major moons in our Solar System could contain some objects with candidates for potentially having orbiting moons of their own. If many of these moons were situated differently, astronomers would define them as planets. read more