Halley's Comet (5/18/06)

Every 76 years, Halley's Comet returns to our cosmic neighborhood. Even though British astronomer Edmond Halley predicted the celestial visitor's appearance in 1758, Halley never saw the comet to which he lent his name. The most famous appearance of the comet -- also known as 1P/Halley -- came in 1910, when it was bright enough to be seen in daylight hours. When the planet passed through the comet's tail on April 18, a worldwide panic erupted as people feared that the Earth's atmosphere would be poisoned by cyanogen gas. The comet's biggest fan may have been Mark Twain, whose birth and death came during visits from Halley's Comet. Twain opined, "The Almighty has said, no doubt: 'Now here are these two unaccountable freaks; they came in together, they must go out together.'" Those wishing to follow Twain's example have plenty of time to make reservations; the comet isn't due back again until 2061.