Rendezvous With Rama - Arthur C. Clarke [2]
There the matter rested for several months, because none of the big orbiting telescopes could be spared from their regular job of peering into the remote depths of the universe. Space astronomy was an expensive hobby, and time on a large instrument could easily cost a thousand dollars a minute. Dr. William Stenton would never have been able to grab the Farside two-hundred-metre reflector for a full quarter of an hour, if a more important programme had not been temporarily derailed by the failure of a fifty cent capacitor. One astronomer's bad luck was his good fortune.
Bill Stenton did not know what he had caught until the next day, when he was able to get computer time to process his results. Even when they were finally flashed on his display screen, it took him several minutes to understand what they meant.
The sunlight reflected from Rama was not, after all, absolutely constant in its intensity. There was a very small variation—hard to detect, but quite unmistakable, and extremely regular. Like all the other asteroids, Rama was indeed spinning. But whereas the normal 'day' for an asteroid was several hours, Rama's was only four minutes.
Dr. Stenton did some quick calculations, and found it hard to believe the results. At its equator, this tiny world must be spinning at more than a thousand kilometres an hour; it would be rather unhealthy to attempt a landing anywhere except at the poles. The centrifugal force at Rama's equator must be powerful enough to flick any loose objects away from it at an acceleration of almost one gravity. Rama was a rolling stone that could never have gathered any cosmic moss; it was surprising that such a body had managed to hold itself together, and had not long ago shattered into a million fragments.
An object forty kilometres across, with a rotation period of only four minutes—where did that fit into the astronomical scheme of things? Dr. Stenton was a somewhat imaginative man, a little too prone to jump to conclusions. He now jumped to one which gave him a very uncomfortable few minutes indeed.
The only specimen of the celestial zoo that fitted this description was a collapsed star. Perhaps Rama was a dead sun—a madly spinning sphere of neutronium, every cubic centimetre weighing billions of tons . . . At this point, there flashed briefly through Dr. Stenton's horrified mind the memory of that timeless classic, H. G. Wells's The Star. He had first read it as a very small boy, and it had helped to spark his interest in astronomy. Across more than two centuries of time, it had lost none of its magic and terror. He would never forget the images of hurricanes and tidal waves, of cities sliding into the sea, as that other visitor from the stars smashed into Jupiter and then fell sunwards past the Earth. True, the star that old Wells described was not cold, but incandescent, and wrought much of its destruction by heat. That scarcely mattered; even if Rama was a cold body, reflecting only the light of the sun, it could kill by gravity as easily as by fire.
Any stellar mass intruding into the solar system would completely distort the orbits of the planets. The Earth had only to move a few million kilometres sunwards—or starwards—for the delicate balance of climate to be destroyed. The Antarctic icecap could melt and flood all low-lying land; or the oceans could freeze and the whole world be locked in an eternal winter. Just a nudge in either direction would be enough.
Then Dr. Stenton relaxed and breathed a sigh of relief. This was all nonsense; he should be ashamed of himself.
Rama could not possibly be made of condensed matter. No star-sized mass could penetrate so deeply into the solar system without producing disturbances which would have betrayed it long ago. The orbits of all the planets would have been affected; that, after all, was how Neptune, Pluto and Persephone had been discovered. No, it was utterly impossible for an object as massive as a dead sun to sneak up unobserved.
In a way, it was a pity.