It's hard to call a path well-worn when something passes by only once every 3,967 years. But it turns out that type of long-period comet can still be tied to a specific meteor shower, as scientists have done with Comet C/2002 Y1 Juels-Holvorcem and the UY Lyncids shower. Comet C/2002 Y1 Juels-Holvorcem most recently made a close approach of the sun in 2003 — which means its last such visit was around 2,000 B.C., when Egypt's Great Pyramids were just a few hundred years old, and its next pass of the sun won't occur until nearly the year 6,000. Looking...