Word: comets
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Since before the dawn of history, Halley's comet has been returning to the vicinity of earth every 76 years or so, intriguing and sometimes bedazzling + earthbound stargazers. Last week marked a turning point...
...This is the first time we've gone to the comet," said Carl Sagan. The Cornell University astronomer was one of about 100 foreign scientists who gathered at Moscow's Institute of Space Research to observe the eagerly awaited rendezvous of the Soviet spacecraft Vega 1 with Halley's comet. At 2:30 a.m. (EST) on March 6, as Vega passed within 5,300 miles of Halley's nucleus and as images of the legendary comet flashed on television screens at the institute, Sagan joined the other foreign scientists in applause, while Soviet scientists and technicians hugged and kissed...
...Soviets were justifiably proud. Their spacecraft -- designed, built and equipped under their supervision by scientists from ten nations -- had become the first man-made object to record close-up views of a comet's coma and nucleus, and send the images and other data back to earth.* It also served as the advance guard for four other craft -- the Soviet Vega 2, the Japanese Suisei and Sakigake, and the European Space Agency's Giotto -- that were to sweep by Halley's in the following week...
Vega 1's camerawork was a triumph of technology. While whipping by Halley's at a speed of 175,000 m.p.h. (relative to the comet), the spacecraft's TV cameras shot some 500 pictures in about three hours. Transmitted across 109 million miles of space, each picture took nine minutes to arrive in Moscow, where it was colored by computer to emphasize differences in brightness. The first images showed only the coma, the great cloud of gas and dust surrounding the nucleus, as a fuzzy, violet-fringed, blue-green ball with a yellow center. But in images that Vega...
...Astronomer Fred Whipple, 79, another American who journeyed to Moscow, the image was further confirmation of his 1950 "dirty snowball" theory, which holds that a comet has a small, solid core of ice and dust. "The fact that the comet's image came out with a bright center shows we were seeing the nucleus," he said. "If that were simply dust, we wouldn't see the irregularities...