The Stars with deep amaze
Stand fit in steadfast gaze,
Bending one way their precious influence,
And will not take their flight.
—J. Milton
CHAPTER 2 – FLY ME TO THE MOON
It did not take long before the promised messenger arrived. She introduced herself as Nimbus, and led Rainbow Dash and Twilight on the ground in deference to Twilight's lack of wings. Nimbus was a white-maned pegasus with a pale blue color. On her haunch was a stylized fireworks-rocket, and she was a few years older than the ponies she had been sent to guide. As Twilight had suspected, their destination was the dome of the observatory. The shutters were wide open, and the inside was darkened. The building was silhouetted against the starry sky, dramatically framed by the flaring trails of meteors.
Twilight tried to ask the messenger what she knew about the Princess' summons, but Nimbus would only reply "I'm not at liberty to say." Nimbus had an air of detached formality about her, a mannerism which Twilight found somewhat impersonal. Her manners and eloquence were, however, unquestionable.
Nimbus had her own questions though, primarily for Rainbow Dash. Apparently, Nimbus had heard more about Rainbow Dash than about Twilight, and Rainbow Dash was certainly in a more talkative mood. Twilight was content to listen quietly to the others' conversation.
"I saw your performance at the Young Flier competition," Nimbus was saying. "Spectacular, if I may say so."
"Thanks!" said Rainbow Dash, a little strut coming to her steps. "I was nervous at first. Well, just a little nervous, anyway."
Both Twilight and Nimbus laughed, though perhaps for different reasons. "A little, yes," Nimbus replied. "It takes some getting used to, being stared at like that, by that many ponies. Funny how it doesn't matter who's watching when things turn serious though, wouldn't you say?"
"Yeah," laughed Rainbow Dash. "Lemme guess, you entered the Young Fliers competition too?"
Nimbus shook her head. "I was too afraid to fly competitively, back then. You're a leg up on me in that regard. I got started late."
Rainbow Dash was going to ask what that meant, but at that moment they arrived at the gates of the observatory grounds. There were two of the palace guards – unicorn guards, Twilight and Rainbow Dash noticed – at the gates. Twilight looked puzzled, as the observatory was not normally considered sensitive even when there was a princess using the instruments. The guards saluted, and one said "They are awaiting inside, Lieutenant Firestreak."
"Fire—" Rainbow Dash froze in mid-step, her wings splaying. "Nimbus Firestreak? Omigosh omigosh omigosh omiGLURK"
Twilight stuffed a hoof into Rainbow Dash's mouth. Nimbus turned around, a silent question on her face. Twilight giggled and asked "I'm going to guess you're a member of the Wonderbolts?"
Nimbus nodded and grinned, "Their most junior member, actually. Beta team alternate. And occasional errand-pony, when I'm out of uniform."
Twilight cautiously withdrew her hoof, ready to put it back if needed. Rainbow Dash was, fortunately, in the 'speechless' phase of her hero-shock. Nimbus took advantage of the moment.
"I need to go," Nimbus said. "The princesses await you, and my uniform awaits me! Perhaps I'll see you later tonight?" she said to Rainbow Dash. A little "squee!" was the only answer. Nimbus laughed, waved a hoof in farewell to Twilight, then leaped into the air and headed toward the tower which the other Wonderbolts had flown earlier.
Twilight had to practically drag Rainbow Dash into the observatory by her tail.

Twilight glanced around as she entered the observation-dome. Things had changed since last she was here. The myriad of smaller instruments, some of which she had duplicates of back in the Ponyville library, had been replaced by a single powerful telescope with a brass gear-festooned tracking mechanism. The oaken floor was as lovingly polished as ever, though, and the elegant high-precision clock was the same as she remembered. A table with books and scrolls was next to the clock, along with an assortment of writing and calculating instruments. Dim marker-lights provided enough illumination for visitors to get about without tripping, and a single shaded lamp on the desk created a small pool of light. Two more palace guards, unicorns like the ones outside, waited quietly and alertly next to the curved dome wall.
The two princesses stood to one side, speaking quietly. It was obvious that Luna was upset; her head was down and her wings extended and low. She seemed like she wanted to hide somewhere. Celestia looked up at Twilight and Rainbow Dash, then beckoned them over.
"Your Majesties," Twilight said as she and Rainbow Dash made small curtseys. "What can we help you with?"
"Thank you for coming." Celestia looked over at Luna. "We need to have something verified. Sister, would you show our friends what you showed me?"
Luna took a deep breath, then stepped over to the telescope. She looked up at the slice of sky the open dome-shutter exposed. Another pair of glowing plasma-trails appeared, then faded. Luna's horn shone dimly for a moment, and the telescope slewed toward what appeared to be the center of the falling stars. She glanced at the telescope's coordinate-rings, looked into the eyepiece for a moment, then stepped back. "Please, look."
Twilight peered into the eyepiece, then gasped. "I've never seen anything like it. That's beautiful... what are they?" Before Luna could answer, Rainbow Dash bumped Twilight aside.
"Lemme see!" Rainbow Dash looked through the telescope, then drew in a deep breath. There were many, many more stars that she could not see with her eyes unaided; they sparkled like a handful of diamonds cast into the night. As her vision adjusted to the dark, she could see washes of faint purple and pink, wispy clouds that she instinctively knew no pegasus would ever touch. The sight was soul-stirring, but it was not the stars or the star-clouds which held attention. Within the field of view were three intense motes of light, each surrounded by a glittering cluster of dim red sparks like tightly-packed swarms of fireflies. "Wow," she said. "That's... awesome."
"Those aren't comets," Twilight said, but not in the self-satisfied voice she usually used when lecturing ponies on matters of magic and science. She was more subdued than normal. "Are these why you asked us here, Princess?"
Luna nodded. "Look again... look carefully." She was obviously trying to not suggest what to look for, not trying to lead the ponies to any particular conclusion. Twilight again approached the telescope, but Rainbow Dash stubbornly would not move away from the eyepiece.
"Hey, I can see them moving!" Rainbow Dash exclaimed. Indeed, the telescope itself was very slowly in motion, tracking the objects.
Twilight looked startled. "That must mean they're very close," she said. Luna and Celestia glanced at each other, then back to Twilight. There was a sudden sinking feeling in the pit of Twilight's stomach. She asked Luna, "Princess, do you have tracking data from earlier?"
Luna's horn glowed, and a notebook with neatly-recorded coordinates levitated up and hovered before Twilight. Twilight looked at the telescope's coordinate-rings to see precisely where it was currently aimed, then at the nearby clock, then back at the numbers within the book. She began calculating, her own horn aglow as a pencil scrawled equations in the margins of the notebook, accompanied by a slide-rule that rapidly generated numbers in response to Twilight's manipulation. Twilight was muttering "...the radial delta... now take the cosine... an eccentricity greater than one? That's hyperbolic! Okay, that means... solve for intersections..." The others watched pensively.
Even Rainbow Dash knew that something serious was happening, though she had no idea what. She felt irritable, largely because she knew that this all was way over her head, both literally and intellectually. She did not have to wait long for an explanation, though. Twilight suddenly let out a gasp, putting a hoof to her mouth.
"What?" Rainbow Dash demanded.
"Just before the dawn?" asked Luna.
"Yes, Princess, about two hours before sunrise," said Twilight in a hushed voice.
Rainbow Dash nudged Twilight. "What is it?"
Celestia closed her eyes, a ripple of sparks flowing down her ethereal mane. "So you were right, Luna. Forgive me for not acting earlier... I had to be sure."
"WHAT?!" Rainbow Dash cried out, her frustration overwhelming her restraint in the presence of royalty.
Twilight turned eyes filled with dread upon her friend. "The... meteors? Whatever they are... they're going to hit Equestria. Tonight."
Luna, her head again lowered, added in a barely-audible voice, "And it's my fault."
...next chapter...