The Planets

We now have 8 planets since Pluto was demoted to a dwarf planet. But did you know that Pluto is not even the largest of the dwarf planets? The knowledge of the Solar System has changed quite a bit in recent decades. When was in high school in the 70’s, I think Jupiter was known to have only 12 moons. Now it has 63.

Here is the order of the planets (8) and dwarf planets (5) along with some interesting facts about each one. By the way, one AU is the distance from the sun to the Earth.

1. Mercury - .38 AU – 4880 km in diameter
2. Venus - .72 AU – 12,100 km
3. Earth – 1 AU – 12,750 km
4. Mars – 1.52 AU – 6800 km
5. Ceres – 2.5-2.9 AU – 950 km
6. Jupiter – 5.2 AU – 143,000 km
7. Saturn – 9.54 AU – 120,500 km
8. Uranus – 19.2 AU – 51,100 km
9. Neptune – 30 AU – 49,500 km
10. Pluto – 29-49 AU – 2274 km in diameter
11. Haumea - 35-51 AU – 1400 km
12. Makemake - 38-53 AU – 1500 km
13. Eris – 96.7 AU – 2450 km in diameter

Not all of the planets have moons and some of the moons have not yet been named.

Earth – 1 – the moon

Mars – 2 – Phobos, Deimos

Jupiter – 63 – Metis, Adrastea, Amalthea, Thebe, Io, Europa, Ganymede, Callisto, Themisto, Leda, Himalia, Lysithea, Elara, Carpo, Euporie, Orthosie, Euanthe, Thyone, Mneme, Harpalyke, Hermippe, Praxidike, Thelxinoe, Iocaste, Ananke, Arche, Pasithee, Chaldene, Kale, Isonoe, Aitne, Erinome, Taygete, Carme, Kalyke, Eukelade, Kallichore, Helike, Eurydome, Autonoe, Sponde, Pasiphae, Megaclite, Sinope, Hegemone, Aoede, Callirrhoe, Cyllene, Kore

Saturn – 60 – Pan, Daphnis, Atlas, Prometheus, Pandora, Epimetheus, Janus, Mimas, Methone, Anthe, Pallene, Enceladus, Telesto, Tethys, Calypso, Dione, Helene, Polydeuces, Rhea, Titan, Hyperion, Iapetus, Kiviuq, Ijiraq, Phoebe, Paaliaq, Skathi, Albiorix, Bebhionn, Erriapo, Siarnaq, Skoll, Tarvos, Tarqeq, Greip, Hyrrokkin, Mundilfari, Jarnsaxa, Narvi, Bergelmir, Suttungr, Hati, Bestla, Farbauti, Thrymr, Aegir, Kari, Fenrir, Surtur, Ymir, Loge, Fornjot

Uranus – 27 – Cordelia, Ophelia, Bianca, Cressida, Desdemona, Juliet, Portia, Rosalind, Cupid, Belinda, Perdita, Puck, Mab. Miranda, Ariel, Umbriel, Titania, Oberon, Francisco, Caliban, Stephano, Trinculo, Sycorax, Margaret, Prospero, Setebos, Ferdinand

Neptune – 13 – Naiad, Thalassa, Despina, Galatea, Larissa, Proteus, Triton, Nereid, Halimede, Sao, Laomedeia, Psamathe, Neso

Pluto – 3 – Charon, Nix, Hydra

Haumea – 2 - Hi’iaka, Namaka

Eris – 1 – Dysnomia