Tiw
Tiw, the fourth planet orbiting I'riuu, was named for Tyr, the Norse god of law and war. The Anglo-Saxon name for this god was Tiw, and is the origin of Tuesday. The red colour comes from iron oxide in the soil, and it is believed that billions of years ago, Tiw may have had oceans. As the planet grew colder, however, these oceans disappeared. Icecaps at both poles remained, and several lakes were formed when terraforming of Tiw began in 43 AUC. Cuurently, 700 million people live on Tiw.
Tiw has one moon, Fortitudo, the Latin word for "bravery" or "courage". It is rather small, and most likely a captured asteroid.
| Ragnarok Mons | Named for the battle in Norse mythology which signifies the end of the world. Ragnarok Mons is the largest mountain in the I'riuu system. |
| Montes Aris | Ares, the Greek god of war |
| Montes Martii | Mars, the Roman god of war |
| Asgard Planitia | The Norse home of the gods |
| Cerberi Planitia | Cerberus, the Greek three-headed dog guarding the entrance to the underworld |
| Gnipa Planitia | The cave leading to the Norse underworld |
| Helheim Planitia | The Norse underworld |
| Northmanni Planitia | The Latin name for Norsemen, or Vikings |
| Terra Fenriri | Fenrir, the wolf-monster bound by Tyr |
| Terra Garm | The hound guarding the entrance to Helheim, will kill Tyr at Ragnarok but will also be killed by Tyr. |
| Terra Gleipniri | Gleipnir, the chain forged to bind Fenrir |
| Terra Pumilii | The Latin word for "dwarves" |
| Terra Sinistra | The Latin word for "left", referring to Tyr's loss of his right hand by Fenrir |