Soror
From Tardis Wiki, the free Doctor Who reference
Soror was the slightly smaller of Trenzalore's two moons and was silver in colour. Since the planet only got minutes of daylight, Soror helped to create lunar-synthesis allowing plant and animal life to grow. (PROSE: Strangers in the Outland)
In an alternate timeline, Soror was destroyed. (TV: The Name of the Doctor)