Moons are objects that orbit planets. Astronomers now count nearly 150 moons around the planets. We find a great variety of natural satellites in our solar system. Some of the larger moons were almost certainly formed at the same time as their parent planet. Others are obviously captured objects with wildly eccentric orbits. Still others orbit near the planet and have the job of keeping planetary rings in line.
Carpe Caelum Planetary Astronomy
Carpe Caelum Planetary Astronomy