Dark Star by Alan Dean Foster

Doolittle." He leaned back and stared outward with that peculiar, farsighted stare Doolittle now knew instantly.
    "Up here, I can watch things, Doolittle. I love to watch things. Just stare at the sun systems and nomad meteors, gas clusters and distant galaxies. You know, I bet I've seen more stars than any human being alive, Doolittle. And you never know what may come tumbling by to say hello in overdrive or hyperdrive. Some of them would surprise you, Doolittle."
    "Yeah," Doolittle mumbled again. Talby was making him increasingly nervous these days. "But you'll have plenty of time for that later, though. I mean, think of it this way: we've been in space twenty years now and we've only aged three years physically, so there'll be plenty of time later for staring around. Won't there, Talby? Talby?"
    "Are we really going into the Veil Nebula region?" the astronomer whispered.
    "Of course we are," Doolittle insisted. "I mean, I gave the order and supervised the course correction, didn't I? It's programmed, isn't it?"
    "You know, Doolittle," Talby said quietly, "if we are going into the Veil region, we may actually find a strange and beautiful thing: the Phoenix Asteroids. They should be passing through there about now, if the predictions are really correct."
    "Oh. Phoenix Asteroids." Doolittle's brow furrowed. It seemed to him that that was a name he should know, a name he'd heard before. It wasn't that he'd cheated his way through the astronomy courses, too. It was just that he hadn't paid much attention to anything but the basics for navigation and plotting. Sightseeing highlights he had kind of glossed over.
    "Phoenix Asteroids?" he confessed finally. "I don't think I ever heard of them."
    Talby gave him a look Doolittle couldn't quite interpret. Anger. Contempt. Pity.
    "They're a body of asteroids—at least, that's what the best guesses think they are—that are running on a definite orbit, but one so vast that for years nobody could calculate it.
    "They were detected right after the development of the first big lunar telescopes. They don't travel in a straight line like most asteroid groupings. Nor do they belong to any one sun system. But they have a true orbit.
    "Once every twelve point three trillion years they circle our universe. They pass through our galaxy in the region of Sol just once, and they'll return in slightly less than twelve point three trillion years from now. But the Earth won't be here to meet them. The Earth may not be anyplace by then. The universe may not be anyplace. But the Phoenix will."
    "Crazy . . . how can anybody calculate an orbit like that?" muttered Doolittle, and then he felt stupid for asking it because, obviously, somebody had calculated it.
    "I don't know, Doolittle. I'm no computer, but it's been done. As for the Phoenix itself, we don't know much about it. Its composition is just a guess. An asteroidal grouping seems as logical as anything for something that defies as many laws as this does." He leaned back in his chair and looked outward, outward. The Phoenix Asteroids . . .
    "They're something different, Doolittle. Something so different we can't even begin to assign an explanation for them. For example, for the scopes on the moon to pick them up visually means they must have their own internal source of light, Doolittle, and an incredibly intense one at that. They glow. Their spectrum changes constantly, the colors on the charts flow like wine. Nobody knows how, or why. By rights, an astronomical object that small should be invisible to us at such distances. You shouldn't be able to detect them from Earth at all, let alone distinguish something like color. But you can, Doolittle, you can."
    Doolittle just stared at Talby, thinking. It seemed to him that he would remember something as spectacular as the Phoenix Asteroids, despite his often lackadaisical approach to some courses. Were they real . . . or another figment of Talby's all-too-active imagination, the product of too much