Word: asteroids
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Later, before Venus becomes too crowded, earthlings might begin to build space cities-at first in orbit around the earth, then around the sun, perhaps using the minerals of the asteroid belt. But soon, even these resources will be exhausted, and the solution may well be to dismantle the giant planet Jupiter. How? Berry recalls a mind-boggling scheme to speed up Jupiter's rotation enough to tear off chunks of the planet; they would then be assembled in a thick band in orbit around the sun. The debris would reflect useful solar energy back toward earth and could...
...much flatter and thinner-rimmed than the moon's and resemble giant pie pans-an indication that they may have been worn down by some yet-to-be-identified erosional process. Like most of their lunar counterparts, Mercury's craters were apparently created by impacts of asteroid-size chunks of material rather than by volcanic eruptions. Indeed, one crater, about 25 miles across, was blasted out of the rim of a 60-mile-wide crater by an impact that threw off raylike splashes of debris...
Jackson and Ryan calculate that if such an object (which would have the mass of a moderate-sized asteroid) intercepted the earth's path at a velocity of about 25,000 m.p.h., it would have set off a shock wave quite similar to the one from the Siberian blast. They re port in Nature that the black hole's passage through the atmosphere would have left a deep blue trail of ionized particles like the streak seen by witnesses near the 1908 blast. Finally, the energy released by the black hole (comparable to that of a ten-megaton...
...December rendezvous with Jupiter, the unmanned spacecraft Pioneer 10 last week finished the 210-day leg of its journey that took it through the asteroid belt. Pioneer. which was launched in March 1972, thus became the first vehicle from earth to pass safely through the vast ring of rocky debris that circles the sun between the orbits of Mars and Jupiter. The relatively uneventful, 200 million-mile passage removed a major concern of both science-fiction writers and scientists: that spacecraft in the asteroid belt would be damaged and perhaps destroyed by flying rocks...
...fragments larger than a grain of sand, and none did any detectable damage to the thinly shielded $50 million craft. By carefully planning Pioneer's trajectory, controllers kept the ship at least 4,000,000 miles from those larger (at least seven miles in diameter) and rarer asteroids that can be seen by telescope on earth. Said NASA's newly confident Dr. William Kinard: "We're firmly convinced that the asteroid belt presents little hazard for future spacecraft going to explore the outer planets...