Each of the eight other planets in the solar system (besides Earth) is named for one of the Titans, as is Earth's moon. Some of these planets were only known through divine revelation until relatively recently (within the last 300 years), and the gods shared very little detail about what these other worlds were like. Whether this is because they wished to keep secrets from their mortal followers or simply because they didn't find the matter interesting is unknown.
The solar system for the Metamor Universe is set up as follows:
Sun
Called "Anor" by the Elves and "Yaj" in the language of the ancient humans. When the aedra and daedra were bound to their spheres of influence by the Elders, the aedra Yajiit became associated with the sun (the name Yajiit and Yaj both relating to the word "fire").
Fallos
Small, hot, rocky planet with no atmosphere.
Moons: None
Amara
Similar in size to Earth, covered in a thick obscuring blanket of clouds.
Moons: None
Earth
Home to our heroes.
Moons: 1, named Celine (seh-LEEN). It is usually just called "the moon" in common conversation.
Mephisto
Rocky planet, colder and a little smaller than Earth.
Moons: 2 small ones, captured asteroids.
Asteroid Belt
Remains of a shattered rocky planet, similar in size to Earth. Legend says that it was destroyed in a battle between the gods and a long-forgotten, nameless evil.
Malekis
Gas giant. Long thought to be the largest of the planets, Malekis is the third-brightest object in the night sky after Celine and Amara.
Moons: More than 50. Four of these are large enough to be seen from Earth with a small telescope.
Nathales
Gas giant. Nathales has a large collection of rings. It was named after the Titan who was bound in chains, which the rings resembled in the eyes of early astronomers.
Moons: More than 50. One of these is large enough to be seen from Earth with a small telescope.
Salestra
An ice planet, and the third-largest planet in the system. It is very dim when seen from Earth and has a slow orbit, so it was not recognized as a planet until the invention of the telescope. It has the coldest atmosphere of any planet in the star system. Salestra has a network of rings, but they are very dark and not normally visible with Earth-bound telescopes.
Moons: More than 20.
Lykos
Ice planet, slightly smaller than Salestra. It was first discovered by observing the "wobble" in the orbit of Salestra that was caused by its gravitational pull. It can be seen from Earth with a small telescope, but it just looks like a small blue-green dot; an observatory-size telescope is needed to make out anything more.
Moons: 13. None are visible with a small telescope.
Reshina
Orbiting on an eccentric elliptical path far outside the rest of the star system, Reshina is a brown dwarf — a failed star, too small to maintain nuclear fusion. Roughly 25 times the mass of Malekis, its presence can be detected through slight wobbles in the orbits of Lykos and Salestra. Every 27 million years it passes close enough to drag millions of comets out of their orbits, sending them careening into the inner star system. Several mass extinctions on Earth have been attributed to cometary collisions triggered by Reshina's influence.
Moons: Unknown. Since Reshina is almost a star itself, it is unclear whether any objects orbiting it would be described as moons or planets.
Sources
Author's Notes
Reshina was inspired by the mostly-defunct Nemesis hypothesis. Sure, it probably isn't true, but wouldn't it be interesting if it were?
While the planets of the Anor System are obviously modeled on our own, I am willing to entertain the possibility of "space fantasy" differences from their real-world counterparts. Perhaps Mephisto is a desert world where most life dwells underground; perhaps Amara has dense jungles and teeming oceans beneath its thick and mysterious clouds. Perhaps the gods, or beings like them, have been busy on these distant worlds, shaping them in accordance with their own desires…