1. Crash of the Century.
If you've gotta go, go with a bang. That's what Comet Shoemaker-Levy 9 did last July. Nearly two dozen mountain-size chunks of this fragmented interplanetary wanderer slammed into Jupiter, creating 2,000-mile-high fireballs and sooty smudges on the planet's cloud tops that were visible from backyard telescopes. Scientists learned much about Jupiter's atmosphere, about comets, and even about how a similar impact on earth might have killed off the dinosaurs. For most onlookers, though, it was just a fantastic show.
Physicists think six types of quarks are the building blocks of all the particles within...