"02 - Birth of an Age" - читать интересную книгу автора (BeauSeigneur James)

"Not all asteroids that enter the atmosphere impact the surface. In the early part of the last century, at 7:00 p.m. local time on June 30, 1908, an asteroid, or perhaps a comet (no one can be certain) entered the atmosphere above the Stony Tunguska river basin in Siberia. That body exploded in midair about seven miles above the earth. Although much about that encounter remains a mystery, it appears that the asteroid or comet was traveling nearly 19 miles per second. Because of its angle of approach, at that velocity, the air would exert a tremendous aerodynamic pressure; apparently when the pressure exceeded the body's compressive strength, it shattered.

'"Even though that body never reached the earth's surface, the force of the pressure when it exploded was equal to a twelve

megaton bomb. It leveled 800 square miles of mature forest; people 45 miles away were knocked down and seared by the heat; the glare was seen for hundreds of miles; and the sound was reported as far away as 600 miles.

"Another even rarer occurrence was actually captured on home movies over Wyoming in the western United States in August of 1972." Dr. Hall directed attention to the display screens which were filled with blue sky and clouds. A low rumble like a distant jet poured from the system's speakers, and then apparently from the cloud in the center of the screen Ч though it was actually high above it Ч emerged a smoky-white luminescent ball followed by what looked like a long trail of vapor. Hall continued, "In this case a large meteoroid, estimated at 200 feet in diameter and weighing about a thousand tons, actually entered the atmosphere and came to within 35.9 miles of the earth's surface. The meteoroid traveled roughly parallel to the earth's surface for just under two minutes, covering nearly a thousand miles, traveling north from Utah to Alberta, Canada, at approximately 31,000 miles per hour, before exiting the atmosphere again. Because its speed never dropped below escape velocity Ч 25,000 miles per hour Ч it was able to pierce the atmosphere and then escape the earth's gravity and continue on its course.

"Now, as to the asteroids presently headed toward earth: based on the albedo, or reflectivity, of each of the asteroids, all three appear to be class-M. Typically, that would make them about 90 percent metal and as much as 10 percent rocky materials. Of the metal content, we expect that about 95 percent is iron and 4 percent is nickel with the remaining 1 percent being other metals. As to their origins, based on their inclination, we believe they are Hungaria-type asteroids Ч noted for their highly inclined orbit Ч from the asteroid belts between Jupiter and Mars, and that they have somehow been diverted from their original orbits. The most detailed images of the asteroids are from the 1,000-foot radio telescope at Arecibo Observatory in Puerto Rico. Recent upgrades to that system provide imaging with resolution of 30 feet or better." Dr. Hall nodded to a staff member who was operating the three large display screens arranged to allow the Primary and Alternate members of the Security Council to see from their places around the table. The staff member pressed the function key to bring up the

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next set of images and the three asteroids appeared in a split screen format to provide the best view of all three asteroids simultaneously.

At this point Dr. Xiou continued the briefing. "We have found no conclusive evidence," he began, drawing attention to the images on the screens, "that the asteroids have suffered a recent collision sufficient to cause a major shift in their orbits. We must conclude, therefore, that some unusual gravitational effect has caused the divergence. The planet Jupiter can play havoc with the orbits of main belt asteroids, but in this case Jupiter must be ruled out as the cause because at the time we calculate that the asteroids left their normal orbits, Jupiter was hundreds of millions of miles away on the other side of the sun. There are, however, a few other theories.

"Based on all our observations and calculations," Xiou continued, "the theory most compatible with the available evidence is that the asteroids have been pulled from their normal orbits by a body small enough to have otherwise escaped our attention as it passed through our solar system. To pull asteroids of this size from their orbits, such a body would have to possess an extremely strong gravity for its size. There are two types of bodies that fit this description: either a small chunk of a white dwarf star, thrown off millions of years ago from a collision of two while dwarfs; or a very small black hole. A white dwarf is a star which, over time, has been stripped of its electrons. Such a star still has most of its mass but it is extremely dense: in its white dwarf stage a star the size of our sun could be compacted to a sphere with a diameter of only 20 kilometers, that is, about 12 miles. If two such stars collided, pieces of the stars would be thrown off at tremendous speeds. Because of its size, a piece of white dwarf could easily pass through our solar system and go completely unnoticed; and if it passed close enough to an asteroid it could certainly disrupt its orbit. The high iron content of all three asteroids tends to lend credence to this hypothesis since some white dwarf stars Ч for example the star 1031+234 Ч are known to possess magnetic fields as high as 700 million gauss, a level which approaches the maximum theoretical strength possible.

"Black holes bear a certain similarity to white dwarfs in that they, too, are produced from objects that have been crushed to incredible densities. The gravitational field of the superdense

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matter that makes up a black hole is strong enough to trap light itself. Most frequently, references to black holes are in terms of those that are as large as our sun or larger because it is known that certain stars collapse in upon themselves to become black holes at the end of their lifetimes. But less massive, smaller holes are also possible. Theoretically, black holes with a mass of a small moon compressed to the size of a few atoms could exist. In appearance a black hole is simply a region of darkness, so a small black hole could easily pass through the solar system without notice. And even the most infinitesimal black hole could have a gravitational field strong enough to pull asteroids from their normal orbits."

The panel continued the briefing as if teaching a class for another twenty minutes, discussing theories, showing charts and simulations, giving historical examples to demonstrate their points. Finally, Ambassador Yuri Kruszkegin of Khakassia, taking advantage of a brief pause, interrupted and asked the question that was on everyone's mind. "Can we conclude from what you've said and the documents you've provided to us, that it is your recommendation that we use nuclear weapons to destroy the third asteroid?" Kruszkegin asked.

"Yes, Mr. Ambassador," Dr. Johnson answered. Alsie Johnson dealt with politicians almost every day; he well knew that while they were among the most long-winded of the human species, they often were among the first to insist that others come to the point. It was time to get to the heart of the matter and Kruszkegin's question provided the opportunity to move the proceedings along.

"What will this involve?" Kruszkegin followed up.

"Because of the risk involved, we feel that redundancy, even overkill, is not only justified, but crucial," Johnson answered.

"I don't think anyone on the planet would disagree with you on that," one of the other members of the Security Council interjected.

"There's certainly no shortage of nuclear devices available for the task," Johnson continued. "Unfortunately, the inventories of launch vehicles capable of reaching the target and delivering a warhead are not nearly so abundant. In order to break free of the earth's gravity and deliver the warheads while the third asteroid is still at a safe distance from the earth, the launch vehicles must be capable of reaching escape velocity, that is, approximately 25,000 miles per hour.

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"Ideally, with enough warning, we would detonate a series of explosions just ahead of the asteroid in order to slow its speed or slightly alter its course. With sufficient time, altering its course even one degree, or its speed by an inch per second, would be sufficient to avert a collision. Unfortunately, at this point we have neither the time nor resources to attempt this. The only option certain to ensure the safety of the earth is to completely destroy the asteroid at the earliest possible moment." Dr. Johnson nodded to Dr. James Stewart of the Ames Research Center at Moffett Field, California, to continue the briefing. Dr. Stewart nodded in turn to the staffer who was operating the display screens.

As the simulation began, Dr. Stewart narrated and explained the action. "When the asteroid is hit by our missiles, the object's mass will be sent flying out in all directions, including some pieces which will continue toward the earth. The farther from the earth the asteroid is when it is destroyed, the greater the mass that will be deflected from entering the earth's atmosphere.

''If any of the remaining parts of the asteroid are very large," Dr. Stewart continued, "they could still pose a threat. Our goal must be to not just break up the asteroid into smaller chunks, but to pulverize it. Our estimates, which are still being refined, are that this will require placement of forty warheads with an average yield of twenty megatons each over the entire earthward face of the asteroid. All of the warheads must reach their target and be detonated simultaneously, an instant before impact with the asteroid. It is a mission uniquely suited to the capabilities of Multiple Reentry Vehicles, or MRVs. This, however, further reduces our inventor}' of acceptable launch vehicles. Specifically, those launch vehicles capable of reaching the target and delivering MRVs are limited to the U.S. Minuteman III and the Russian-built SS-11 Sego. Further complicating the problem is that these are both relatively old systems and most have been converted to heavy lift vehicles for orbital launches, or have been destroyed to comply with treaties. Additionally, both the Minuteman III and the Sego will require considerable modification for this mission.

"Our plan at this point is to send three waves of missiles so that, should the first volley fail to completely destroy the asteroid, a second and third line of defense will stand ready to finish the job." As the simulation showed second and third waves of missiles

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destroying the few remaining large pieces of asteroid, Dr. Stewart concluded by noting that all of the technology employed was proven and that all those involved were certain of the plan's feasibility.