Once upon a time, there were two beautiful princesses: the Sun and Moon. Their jobs were to watch over all Creation, in a constant, vigilant cycle. During the day, the Sun would stand guard, patrolling across the sky. At dusk, she would rest, and the Moon would take watch over the night. She would walk the same route, until dawn, when the Sun awoke once more to relieve her shift.
The two never spoke, only exchanging a nod or glance across an infinite distance, when one took the other's patrol. Still, something eventually happened. As Creation existed for eons and eons, they grew fond of each other. Who else could relate to the solemn, yet boring, duties that they shared? They were the only creatures who could understand each other.
Of course, it could not be that simple. For all its compassion, Love can be cruel. In this instance, its sense of humor was a bitch. "Oh, let's force these two to be apart, all the time! That should be fun!" What an asshole.
Luckily, the Universe had other plans. With a bit of nudging, and a couple stitches in the fabric of space time, their orbits were altered. Once every few centuries, the two would get to meet, at a fucking spectacular party: the Eclipse.