"... Was that really necessary, Luna?" Celestia asked.
Luna set the newspaper on the dining table the sisters shared, trying to look innocent, "Whatever do you mean, dear sister?"
Celestia narrowed her eyes and pointed to the newspaper with her royal hoof, directing Luna's attention to the front page. There in black and white was a large image of Rainbow Dash on the surface of the moon, looking like a startled cat in her space suit while the flag of Equestria stands cock-eyed in front of her. The headline is 'First pegasus on the moon arrives safely!'
"You know what I mean." Celestia frowned at her sister's poor lie, "Why'd you tamper with what should have been a momentous achievement for ponykind?"
"What do you mean? Going to the moon? Was there something special about doing there?" Luna tapped her chin, "If they wanted to go I could have just sent somepony there..."
Celestia sighed, "Luna, you aren't offended about... me sending you to the moon are you?"
Luna quickly dropped her factitious tone and shook her head, "Wha- no sister, my ire is not at you! You had no choice in that matter. No. What vexxed me was thy student and her rainbow-maned friend."
Celestia blinked, "What could Twilight and Rainbow Dash done to deserve such passive aggression?"
Luna raised an eyebrow, "You recall my complaints about Twilight Sparkle's projections on where the safest place was to land their ugly little 'lander'?"
Celestia thought back to all those meetings with Twilight, mostly they were technical jargon that she nodded her head at but didn't actually understand.
"I remember you wanting Twilight to land near what astronomers call the 'Sea of Harmony' but she said it wasn't the best place to land, and you being adamant about her not landing in a patch of bare rock." Said Celestia.
"Bare rock my hind hoof," Luna snorted, "I spent a thousand years on the moon, and I had to kill time somehow."
Celestia tilted her head, but allowed Luna to keep talking.
"I even offered to teleport Twilight Sparkle's little toy all the way to the moon to keep her off my property, but noooo... she had to do it the non-magic way because 'it was a challenge.'" Luna blew a raspberry, "The little purple smart had to have it her way despite the fact I had that area of the moon very clearly cordoned off and signs put up."
"What... kind of signs?" Celestia asked, still lost.
With a tired sigh Luna lit her horn and in a flash of blue a stone-crafted sign appeared atop the royal breakfast table which clearly said 'Nightmare Moon's Princess Luna's rock garden. KEEP OUT.'
"Because of that flag and the disruption Twilight Sparkle's lander caused, I'm going to have to completely redesign my precious rock garden." Luna fumed.
Celestia sipped her tea, at last understanding the problem, "The lander managed to land your rock garden? I suppose I'd be annoyed too if something had destroyed my own statue garden."
"Your 'garden' is a mere twenty by twenty yards." Luna narrowed her eyes, "My rock garden is several hundred miles across."
Celestia nearly choked on her tea, "Several hundred miles..."
"Well, I WAS up there for a long, long time..." Luna sighed.
Celestia slumped back into her chair, "... would you like some help rearranging it?"
"Certainly." Luna's smile widened.
---
Several days later, on the surface of the moon
---
Twilight Sparkle was not happy. She'd been moving rocks from one patch of dust to another for hours.
"Keep working Twilight Sparkle. We have many more concentric circles to form!" Luna cheerfully cried out, "They are a most pleasing design!"
Twilight sighed and picked up another group of rocks with her magic. Maybe she should have tried going to Mars instead...