The Outer Senshi consist of Uranus, Neptune, Pluto and Saturn. They protect the solar system from evil. During the Silver Milenium they kept their distance from the Inners and watched out for them from a far. The Outers were never meant to be reborn, but they somehow were! Good thing too, the Outers have a lot more powers than Inners and the Inners seriously need the Outers help! The Outers have special castles above their planets. They were created for them by Queen Selenity to keep the Outers away from the Inners and give the Outers a place to stay!
FYI: If you see on other pages Tenou, Meiou, and Kaiou, they're INCORRECT SPELLINGS! The person is using the Hiragana (which isn't as accurate), they SHOULD use the Kanjii, making it Oh!(also if you look at all the romanjii spellings in the Anime and Manga it's spelled with the Oh. That seems to tell me that, that is the prefered spelling!)