A few minutes before 5:00 a.m. Eastern Standard Time on December 24th, the 170-kilometer-wide minor planet 334 Chicago passes in front of the 8.5-magnitude star SAO97327 in Gemini. The nominal path for this event crosses Philadelphia (at about 9:57 Universal Time) and continues westward across Lake Michigan, just north of the city after which the asteroid is named. It passes through Regina and inbetween Calgary and Edmonton in Canda before entering southern Alaska. A detailed map of the occultation path is now available.
Events like this can be timed by observers using small telescopes or recorded using an inexpensive video camera aimed into a telescope. David W. Dunham, president of the International Occultation Timing Association, explains these techniques in the article "Camcorder Timing Tips."
Other occultations by asteroids in 2002 were predicted by Dunham in his article "Planetary Occultation Highlights for 2002." In the days leading up to an event, more detailed information is often posted in IOTA's asteroid section and sent out in a Sky & Telescope AstroAlert issued by Dunham.