Varda commanded the Moon to journey in like manner, and passing under Earth to arise in the east, but only after the Sun had descended from heaven. But Tilion went with uncertain pace, as yet he goes, and was still drawn towards Arien, as he shall ever be; so that often both may be seen above the Earth together, or at times it will chance that he comes so nigh that his shadow cuts off her brightness and there is a darkness amid the day.
^ @White_Rabbit