Word: cometted
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...Halley's comet began its swing around the far side of the sun in early January, it disappeared from view, not to be visible from earth again until after it emerged from the sun's glare in mid-February. Unfortunately for earthbound observers, it was during that unseen passage that Halley's put on its most dramatic display so far. As the comet neared its Feb. 9 perihelion, its closest approach to the sun (about 55 million miles), the searing solar rays caused increasing amounts of material to evaporate from its icy surface. Eventually the comet's enveloping gas cloud...
...fact, Halley's spectacular show did not go entirely unobserved. Last week scientists at NASA's Ames Research Center in California proudly displayed computercolored ultraviolet images of Halley's hydrogen coma as it appeared between Feb. 2 and 5, and described the changes in the comet during its most active period...
...data used to create the image had arrived in California by an unusual route. Looking for ways to view Halley's comet at perihelion, Ames scientists had hit upon the idea of using the Pioneer 12 spacecraft, which has been orbiting Venus since December 1978, surveying the planet with an array of instruments. Around the time of Halley's perihelion, they realized, Venus--and thus Pioneer--would be in position to have a direct view of the comet. Late in December the scientists ordered the spacecraft to pivot 90 degrees and point its ultraviolet scanner at the comet...
Pioneer will continue to observe Halley's, measuring water loss and looking for oxygen, carbon, sulfur and other elements in the coma's gases, until March 6, when the sun will begin blocking the Venusian view of the comet. On that day, however, the first of an international flotilla of spacecraft will take over Halley's vigil. The Soviet probe Vega 1 will fly through the coma, passing within 6,000 miles of the nucleus. It will be followed by another Soviet craft, two Japanese probes, and the European Space Agency's Giotto, which will make the most daring pass...
...mission specialist on last week's flight, Resnik was supposed to help take photographs of Halley's comet, among other tasks. She was also carrying a signet ring for a nephew and a heart-shaped locket for a niece. "I think something is only dangerous if you are not prepared for it," she once said of space travel, "or if you don't have control over it or if you can't think through how to get yourself out of a problem." For Resnik, danger was simply another unknown to be mastered...