The year’s celestial highlight now starts its parade through the predawn sky. It’s Hale-Bopp, visible to the naked eye low in the northeast. More than any other denizens of the cosmos, comets cause astronomers to gobble down antacid tablets. With just a few observations, we can know precisely where a comet will be and how fast it’ll move. But the appearances of the comet, unlike those of Neptune or the vice president, are unpredictable. This lends comets intrigue and charm. It also drives the experts bonkers.
Case in point: Last September Hale-Bopp dimmed for a few weeks. Was this just a lull in the outgassing--the process whereby the comet’s ice-ball nucleus weaves its tail? Or was Hale-Bopp finally showing its true, drab colors? Astronomers, who had been predicting the best comet in more than a decade, began hedging their bets. But in October, Hale-Bopp obediently (and just as mysteriously) returned ...
