Word: cometted
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
This cloud, which can grow to thousands of miles across, is the comet's head, the light-reflecting shroud that turns an otherwise insignificant iceberg into a brilliant object. Just how brilliant depends on many factors. The solid comet's size is one, and Hale-Bopp, an estimated 20 miles across, is bigger than most. (Halley's was less than half as large.) Its history is another. Out in deep space, a comet can get encrusted with a layer of gummy dust. This layer can seal in most of the ice and prevent it from vaporizing. Some gas may spurt...
...maybe the comet has been around the block too many times. The first visit loosens a comet's crust, making later go-rounds more impressive. If the comet comes through too often, however, a new crust can form out of dust falling back onto the surface. This too can lead to false optimism. "With Comet Halley, which has been back many times," says University of Texas astronomer Anita Cochran, "only about 15% to 20% of the surface is active." Admits Hale: "It's been kind of nerve-racking to sit through all those months wondering if the comet would fizzle...
...didn't. Hale-Bopp has steadily grown in brightness, giving amateur astronomers an increasingly satisfying show. Professional astronomers too have been watching Hale-Bopp, and not always with detachment. "We're delirious," says Tobias Owen of the University of Hawaii. "It's been 20 years since a really bright comet came by, and now, within just a year, we've had Hyakutake and Hale-Bopp...
Astronomers also believe a comet impact is probably what did in the dinosaurs 65 million years ago. That object was perhaps 10 miles across. At double the size, Hale-Bopp packs a lot more potential energy. Luckily for civilization, Hale-Bopp will miss Earth by 120 million miles...
...gods to sweep the heavens free of evil. In the West they were believed to presage the fall of Jerusalem, the death of monarchs and such anomalies as two-headed calves. The Norman Conquest of England was attributed to the 1066 flyby of Halley's, history's most famous comet, which has been linked to everything from Julius Caesar's assassination to the defeat of Attila the Hun. Told that Earth would pass through Halley's tail during its 1910 visit, many Americans panicked and bought gas masks and "comet pills...