Dinah considered it for a few moments, then broke eye contact and looked at her radio. “Sean does,” she said.
“I’m not sure I heard that correctly,” Doob said, after a long, groping pause.
“The Eight Ball,” she said. “That’s what Sean calls it. It’s a rock you don’t know about. One you can’t see coming. It’s too dark, too far away.”
“Dinah, I’m confused—are we talking about a hypothetical asteroid here, or—”
“No. A specific one. A real one. Look, Doob, you know that Arjuna Expeditions has been putting up cubesats for years. We have hundreds of eyes in the sky, drifting around taking pictures of near-Earth asteroids, cataloging them, recording their orbital parameters with as much precision as we can manage. Well, apparently he’s been lying awake at night thinking about the same stuff as you. The extreme instability of the debris cloud. Its sensitivity to any kind of perturbation. And he had the bright idea: Why not search through Arjuna’s secret database of asteroids to see whether any bad actors were going to be passing through the middle of the lunar debris cloud during the next couple of weeks, when it’s on such a hair trigger?”
“He has that database with him?”
“Sure, whatever, it’s just a spreadsheet.”
“So he opened that spreadsheet and did that analysis?”
“Yeah. Doob, listen, I’m piecing this together from circumstantial evidence. You’ve seen how spotty the communication is.”
“Understood.”
“But I think he did that analysis and found an asteroid, which he is calling the Eight Ball. I assume it’s low-albedo.”
“Black. As eight balls are,” Doob said.
“I don’t know anything about its size or its orbital parameters, any of that. But Sean thinks it’s going to pass right through the middle of the cloud in about six hours.”
“Six hours?!”
“And that it has enough kinetic energy to be, well, interesting.”
Doob was thinking about Amelia. About those emotions that had kept him awake earlier. Predictably, everything had now been reversed and he was terrified that she and Henry and Hesper and Hadley were all about to die.
Dinah misinterpreted this as him making astronomical calculations in his head. “I’m going to go and get six hours of sleep,” she said. “Good night.”
“Good night, Dinah,” Doob said.