Chapter 18 Chapter 4 Crossing the Asteroid Belt

Week after week, Discovery 'swept the orbit of Mars and headed for Venus like a streetcar on a perfectly predetermined track.Unlike all vehicles in Earth's skies and oceans, it requires absolutely no manipulation, even the tiniest. Its course is determined by the laws of gravitation; no unmarked bar or reef will ground it.Nor is there the slightest danger of colliding with other ships; for no other vehicles—at least no other artificial ones—are between it and the infinitely distant planet. However, the space it now enters is far from empty.Ahead is no man's land, criss-crossed by the trails of more than a million asteroids—less than 10,000 of which have orbits accurately calculated by astronomers.Only four of them were larger than a hundred miles in diameter; most were nothing more than gigantic boulders rolling through space.

There is simply nothing that can be done about these asteroids; although the collision of the smallest of them at tens of thousands of miles per hour would completely destroy the spacecraft, the chances of such a collision are almost non-existent.On average, there is only one planet in a million-mile-square patch of space; and that Discovery should happen to be occupying that same spot at the same time is really the least of the crew's worries. On the eighty-sixth day, they will travel the closest distance of any known planet.The unnamed planet—just Planet 7794—was a fifty-yard-diameter monolith discovered by the Lunar Observatory in 1997, long forgotten by all but the patient computers at the Asteroid Bureau. exist.

As soon as Bowman started his watch, Hal reminded him of what he was about to face--not that he might forget the only scheduled event of the entire voyage.The relative positions of the orbits of the planets and the stars, and the coordinates of their closest approach, were already displayed on the various screens.Next to it is a list of planned or experimental observations; when 7794 flies by at a relative speed of 80,000 miles per hour from a distance of only 900 miles, they will have a lot of work. When Bowman asked Hal for the telescopic lens, a sparse field of stars appeared on the screen.Nothing resembling a planet can be seen on it; all shapes and shadows are enlarged to the largest extent, and they are just spots of light that do not take up space.

"Give me the target crosshairs," Bowman offered.Immediately, four faint thin lines appeared on the screen, encircling a small, indistinct planet.He stared at it for many minutes, wondering if Hal might have been mistaken; then he saw the pinpoint of light moving so slowly that it could only be detected by the position of the stars in the background.It may still be half a million miles away—but its movement proves that, by cosmic distances, it's close enough to touch. When Poole came to the console six hours later, 7794 was already hundreds of times brighter than before, and it was moving quite quickly from the background, so it could never be mistaken again.It also ceased to be a point of light; it began to appear as a clearly identifiable disk.

They stared at the boulder that flashed in the sky, and the emotion was comparable to that of sailors who looked at the coast from a long time across the ocean and could not land.Although they clearly know that 7794 is just a rock without living things and air, this kind of knowledge can hardly influence their feelings.On this side of Venus, still two hundred million miles away, it was the only solid matter they could see. Using high-powered telescopes, they could see that the asteroid was irregular and moving slowly.At times it looked like a flat ball, at other times a crude brick; its cycle was a little over two minutes.Its surface is speckled with bright and dark spots, apparently without regularity, often like a distant window, or a flat or protruding part of a crystal, shining in the sunlight.

The asteroid was hurtling past them at thirty miles per second; they had only a few minutes of frantic close-ups, a dozen pictures taken by the automatic camera, and the echoes from the navigation radar carefully monitored. Recordings are made for future analysis - at that moment there is only time for a contact probe. The test did not use instruments; no instrument could withstand such cosmic velocity collisions.Just shoot a small piece of metal from Discovery in a direction that should intersect the planet's orbit. In the seconds before contact, both Poole and Bowman waited with increasing tension.Although this experiment is very simple in theory, it is the most rigorous test of the accuracy of the equipment.They fired at a target only a hundred and fifty feet in diameter from a distance of thousands of miles.

In front of the dark part of the planet, there was a sudden burst of dazzling light.The little strip of metal hit it at the speed of a meteor; in a fraction of a second, all of its energy was converted into heat.A plume of hot gas briefly bubbles into space; Discovery The camera above recorded the rapidly fading magic light.Back on Earth, experts will analyze it for telltale signs of burning nuclei.As a result, the composition of an asteroid's outer shell has been identified for the first time. Less than an hour later, 7794 gradually disappeared again, and no trace of the disk could be seen.

By the time Bowman was next on duty, it had completely disappeared. Once again they were alone until three months later the outermost moons of Jupiter swayed toward them.