David Levy, Jarnac Observatory
Hung be the heavens with black, yield day to night!
Comets, importing change of times and states,
Brandish your crystal tresses in the sky. (1.1.2-3)
–William Shakespeare, I Henry VI
In the opening lines of one of William Shakespeare’s earliest plays, the great amateur astronomer, as I like to call him, wrote about the majesty of comets. When he wrote that comets import change of times and states, he had something else in mind other than a comet literally plowing into Earth, with devastation so great as to destroy most of life here. Usually no larger than a village, a comet moves about the Sun, slowly and faintly when it is far away, then more quickly and becoming more active and luminous as it closes in from a place beyond Jupiter — plummeting past the orbits of Mars and the Earth.
Those of us who saw spectacular comets in 1996, 1997, 2007, and hopefully this year, will not soon forget those almost fearsome sights in the heavens. In March 1996, Comet Hyakutake, the first of two prominent comets that year, sported a ...