There are at least 61 natural satellites of planets in the Solar System. Each moon is much smaller than its planet.
Earth's Moon is one of the larger natural satellites with a diameter of 2,160 miles. It is the only moon close enough to us that details of its surface can be seen through a telescope from Earth.
Largest. The largest moon is Ganymede with a diameter of 3,280 miles. That means that Ganymede is even larger than either of the major planets Mercury and Pluto. Saturn's moon Titan, shown at left in a Voyager 2 photo, is the second largest moon in the Solar System with a diameter of 3,200 miles. That's twice the size of Earth's Moon.
Smallest. The smallest moon is Deimos, one of two moons of Mars. Deimos is only seven miles in diameter. It's possible there are smaller shepherd moons yet to be counted and named in the rings around Saturn and other giant gas planets in the outer Solar System.
Charon is the moon closest in size to its planet, Pluto. Earth's Moon is second in that comparison.
Moons of the Solar System PLANET MOONS MOON NAMES Mercury 0 Venus 0 Earth 1 Moon Mars 2 Phobos, Deimos Jupiter 61 Io, Europa, Ganymede, Callisto, Amalthea, Himalia, Elara, Pasiphae, Sinope, Lysithea, Carme, Ananke, Leda, Metis, Adrastea, Thebe, Callirrhoe, Themisto, Kalyke, Iocaste, Erinome, Harpalyke, Isonoe, Praxidike, Megaclite, Taygete, Chaldene, Autonoe, Thyone, Hermippe, Eurydome, Sponde, Pasithee, Euanthe, Kale, Orthosie, Euporie, Aitne, plus 23 to receive names Saturn 31 Titan, Rhea, Iapetus, Dione, Tethys, Enceladus, Mimas, Hyperion, Prometheus, Pandora, Phoebe, Janus, Epimetheus, Helene, Telesto, Calypso, Atlas, Pan, Ymir, Paaliaq, Siarnaq, Tarvos, Kiviuq, Ijiraq, Thrym, Skadi, Mundilfari, Erriapo, Albiorix, Suttung plus 1 to receive a name Uranus 27 Cordelia, Ophelia, Bianca, Cressida, Desdemona, Juliet, Portia, Rosalind, Belinda, Puck, Miranda, Ariel, Umbriel, Titania, Oberon, Caliban, Sycorax, Prospero, Setebos, Stephano, Trinculo, plus 6 to receive a name Neptune 13 Triton, Nereid, Naiad, Thalassa, Despina, Galatea, Larissa, Proteus, plus 5 to receive names Pluto 1 Charon TOTAL 136
Solar System: The Sun Inner System: Mercury Venus Earth Mars Outer System: Jupiter Saturn Uranus Neptune Pluto Other Bodies: Moons Rings Asteroids Comets
