The Planet With No Moon

She looked at the ceiling of the hall, a digital starry sky. Normally it would show the sky of Ymir, or at least what one would see if it had been night, a night that would never come. But right now, once a year, it showed the sky of the old world. And all around her were older people, those that had seen this sky for real, that missed it despite having forsaken it.
How different it was to her, to all the Ymirborn. Who had grown up underneath an eternal sun, knowing that the darkness was too cold to see the night, whose only experience with a day-night cycle was the simulated one inside their homes. And where nothing ever would block the sun, as Ymir had no moon.
They said Earth's moon was one of the largest of its kind, relatively. That there were theories of it originating from a crash with another planet, believable ones but not entirely proven yet. That the full moon was a thing of beauty, while a new moon brought with it an intimidating darkness, which one could only experience outside the cities.
She would never truly know the thing called light pollution. And none of them would ever see it again. This always had been a one-way trip. And she knew that to all of them, it had been worth it. But every year, many would come here, to reminiscence, to shed a tear, to mourn the moon.