The Shell We Live Inside

The comet had been hanging over the highway for an hour, a smudge with a faint tail, and neither of them could stop looking at it.

"Dad said it came from way out there," Soren said. "Past everything."

"Past Pluto?"

"Way past Pluto. He said there's a whole cloud of them. The Oort Cloud." He had the map light on and his notebook open on his knee, the pages tilting every time the car took a curve.

"So show me where it is." Maya pulled his phone over. "On the picture of the solar system."

Soren found one. The sun in the middle. The eight planets in tidy rings. A dotted line past Neptune for Pluto and the other icy leftovers.

"Okay," Maya said. "Where's the cloud."

Soren scrolled. The picture ended. He found another. It ended too, at the same place, just past the planets.

"It's not on here."

"Zoom out."

"There's nothing to zoom out to. The picture stops."

Maya frowned at the windshield. "But the comet's real. It's right there. Something threw it at us."

"Nobody threw it. It just fell." Soren read for a second. "They think the cloud is a giant ball around the whole solar system. Not a ring. A shell. All the way around, top and bottom and sides."

"How big."

He read again, then read it twice more because the number would not fit the first time.

"A quarter of the way to the next star."

Maya turned around and looked out the back window, at the dark behind them, like she could check.

"Say that in cars," she said. "How many hours of driving."

"You couldn't. Not in your whole life. Not in a hundred lives." Soren pressed his pencil into the page. "And they think there's two trillion comets in it."

"Two trillion."

"Give or take."

Maya was quiet. Then: "How do they count them if they're that far?"

Soren scrolled down. He kept scrolling. He went to a second page and a third, and the map light made a little tent of yellow over both of them.

"That's the thing," he said slowly. "They don't."

"Don't what."

"Count them. See them. Any of them. Nobody's ever seen the cloud."

Maya took the phone back and read it herself. Her lips moved. She read it again.

"Never," she said.

"Not once. It's too far and the comets are too small and too dark. No telescope has ever looked at it and gone, there, that's the Oort Cloud."

"Then how do they know it's there?" Maya's voice had gone sharp, the way it did when a thing did not sit right. "You can't just decide there's a giant ball around us."

"That's what I'm trying to find out." Soren flipped his notebook to a clean page. He drew the sun. He drew the comet, a little dash with a tail, coming in toward it. "Okay. The comets that fall in. Like this one. Where do they come from?"

"Out there. You said."

"But which direction out there." He looked up. "That's it. That's how."

"What's it."

"The comets that fall in. If they all came from a flat ring, they'd all come in flat, along the same plane as the planets. Right?" He drew arrows coming in sideways, all in a line.

"Okay."

"But they don't. The long ones, the ones that take forever, they come from every direction. Straight down. Straight up. Sideways. Every angle there is." He scribbled arrows now, all over the sun, from everywhere at once, a pincushion of them.

Maya watched his hand. "So if they fall in from every direction."

"Then they have to be sitting out there in every direction. To start with. Before they fall."

"A ball," Maya said. "Not a ring. A ball. Because that's the only shape that's got stuff in every direction."

"A shell," Soren said. "A ball would be full. This is hollow. We live in the hollow part."

Maya sat back. The comet slid a little across the windshield as the road turned.

"So nobody saw it," she said. "They saw the ones that fell out of it. And they came from everywhere. So the everywhere has to be there."

"Yeah."

"That's not guessing." She said it like she was defending someone. "That's not just deciding. The comets told on it."

Soren grinned at his page. "The comets told on it."

Maya looked up through the windshield glass, and then she did something Soren didn't expect. She tipped her head back against the seat and looked up, at the roof of the car, like she was looking through it.

"It's over us right now," she said. "The shell. It's up there and it's down under the road and it's out past both windows. All the way around. And it's so far the picture won't even hold it and nobody's ever seen it and it's still there. We're inside it. We've been inside it the whole time."

"Two trillion of them," Soren said quietly. "Just sitting in the dark. Waiting to maybe fall."

"And one of them fell." Maya pointed at the smudge. "That one. Out of the whole ball, that one came all the way down here so we could see it, so we'd know the rest were up there."

"We don't know it's from the Oort Cloud for sure. This one might be closer."

"I know." Maya kept her eyes on it. "But some of them are. Some of them come from a place we've never seen and never will and it's real anyway."

Soren looked down at his drawing, the sun surrounded on every side by arrows pointing in, and then he added one more thing. A tiny dot, way out past all the arrows. Then he stopped, because there was no edge to draw, and the page just went white in every direction around it.

Outside, the comet held its place above the road, and the dark on all sides of the car went on and on and did not end.