Comet Hyakutake shows off its long, bright tail in this image from March 25, 1996. The comet passed less than 10 million miles from Earth on that date, which was the closest passage by any comet in two centuries. Hyakutake had been discovered just two months earlier by an amateur astronomer in Japan. By the time of its closest approach it was an easy target for the unaided eye, even from most cities. It was moving so fast, though, that it quickly faded from sight. It isn't expected to visit the inner solar system again for another 70,000 years. [E. Kolmhofer, H. Raab/Johannes-Kepler-Observatory, Linz, Austria]