Gallery: NASA ready to shoot the moon

This half of the Earth will be faced toward the moon at about 4:30 a.m. PDT when LCROSS plunges into the lunar surface. NASA is planning a series of parties at observatories and museums across the U.S. to observe the event with experts.

Excellent lighting conditions are expected in the Mountain, Pacific, Alaska and Hawaii time zones. In the Central time zone, the best viewing will be west of the Mississippi, and daybreak in the Eastern time zone will prevent viewing the plume.